Who Wants Better Gas Milage?

[NorCalRacer]

PEOPLE SEEM APPALLED BY THE PRICE OF GAS THESE DAYS. THERE ARE MANY GIMMICKS OUT TODAY: MAGNETS, TORNADOES, WATER INJECTION, ETC. MOST HAVE NO EFFECT OR NEGATIVE EFFECTS. I HAVE WORKED ON VEHICLES FOR ABOUT 10 YRS NOW AND HERE ARE SOME METHODS THAT GURANTEED WORK. BTW, IT IS EASIER FOR ME TO TYPE IN CAPS SO IF YOU DON'T LIKE CAPS DON'T READ THIS PLEASE, I DON'T WANT TO WASTE MY TIME TALKING ABOUT MY TYPING, THIS IS TO HELP PEOPLE.

1: PREMIUM GAS. IF YOU HAVE AN OLDER VEHICLE CHANCES ARE THE GAS WAS A LOT BETTER WHEN IT WAS MADE. MORE OFTEN THAN NOT, YOUR DOLLAR WILL GO FURTHER WITH THE BETTER GAS.

2: SMOG, VACUUM SYSTEM. WHETHER CARBURETED OR INJECTED, ALMOST ALL VEHICLES HAVE SOME FORM OF VACUUM/ SMOG SYSTEM RUNNING ON THE MOTOR. IF YOUR MOTOR DOESN'T WARM UP PROPERLY OR IF ANY OF THE SMOG UNITS (EGR VALVE. AIR PUMP, CHECK VALVES, O2 SENSOR ETC) AREN'T FUNCTIONING PERFECTLY YOUR MILEAGE WILL REALLY SUFFER.

3: ELECTRIC FAN. IF YOUR VEHICLE ISN'T ALREADY EQUIPPED WITH ONE, INSTALL A THERMOSTATICALLY CONTROLLED ELECTRIC FAN. THESE ARE EASY TO INSTALL, COST ABOUT $200 AND FREE UP A SIGNIFIGANT AMOUNT OF HORSEPOWER MAKING YOUR ENGINE NOT HAVE TO WORK AS HARD.

4: EXHAUST LEAKS. A BAD EXHAUST LEAK WILL TAKE BACKPRESSURE OFF YOUR ENGINE AND MAKE IT RUN IMPROPERLY.

5: AIR CLEANER AND SPARK PLUGS OBVIOUSLY

6: SUSPENSION/TIRE PRESSURE. A SOFT SUSPENSION WILL ROB POWER MAKING YOUR ENGINE WORK HARDER.

7: OIL. DIRTY OIL ROBS GAS MILEAGE AND KILLS YOUR ENGINE. CHANGE EVERY 3000 MILES.

I HAVE A FULL SIZED CHEVY TRUCK WITH A 4.3 L V-6 IN IT AND I ALMOST GET THIRTY MILES TO THE GALLON. I THINK PEOPLE WOULD BE AMAZED THE MILEAGE THEY COULD GET OUT OF A VEHICLE THEY ALREADY OWN INSTEAD OF BUYING A NEW ONE.

IF ANYONE ELSE KNOWS SOME TRICKS PLEASE POST THEM HERE, I WOULD LIKE TO TRY THEM OUT.

[400exrules]

yah....dont drop the hammer everywhere you go, that will help too;)

[JIMTED79]

I have a 94 toyota pick up with a 22re and have tryed both 87 and 91 octaine trying to see a difference and did not. Got the same mileage so I went back to 87 octaine.

[NorCalRacer]

MY MAGIC DOESN'T WORK ON EVERYTHING. HOW LONG DID YOU TRY THE BETTER GAS? I THINK IN LA YOU GET TESTED EVERY FEW YEARS RIGHT? YOUR LAST SMOG IS PROBABLY A GOLDMINE OF INFO. IF YOU COULD PM SMOG RESULTS TO ME I MIGHT HAVE A CLUE. COULD JUST BE AN EXCEPTION TO THE RULE AS WELL.
THANKS FOR RESPONDING, I WOULD LIKE TO SEPERATE THE MYTHS FROM FACT AND HONEST INPUT HELPS.

imgonna get 93 next time when i fill upe anis premium=$0.20x15 gallons? ....well its only like $3.00 difference which aint that bad.

[JIMTED79]

Originally posted by NorCalRacer
MY MAGIC DOESN'T WORK ON EVERYTHING. HOW LONG DID YOU TRY THE BETTER GAS? I THINK IN LA YOU GET TESTED EVERY FEW YEARS RIGHT? YOUR LAST SMOG IS PROBABLY A GOLDMINE OF INFO. IF YOU COULD PM SMOG RESULTS TO ME I MIGHT HAVE A CLUE. COULD JUST BE AN EXCEPTION TO THE RULE AS WELL.
THANKS FOR RESPONDING, I WOULD LIKE TO SEPERATE THE MYTHS FROM FACT AND HONEST INPUT HELPS.

To be honest I only ran one tank of the good stuff, could that be why I did not see a difference? As for smog results I have owned the truck only a little over a year and the guy smoged it just as I bought it so I have no info on that.

[NorCalRacer]

I WOULD TRY A COUPLE OF TANKS. SOME VEHICLES HAVE "ON THE GO" COMPUTER SYSTEMS THAT CONSTANTLY CHANGE THE MOTOR MAPPING BY THE INPUT FROM THE SENSORS. I DO NOT KNOW MUCH ABOUT TOYOTAS BUT IF YOU HAVE COMPUTER CONTROLLED TIMING I WOULD GO A COUPLE OF TANKS. IT IS WORTH THE RISK OF $6 OR SO, SO FAR I HAVE SEEN ONLY A FEW VEHICLES THAT DIDN'T BENEFIT FROM THE BETTER GAS.
IF YOU HAVE HEI WITH MANUAL TIMING, I WOULD CHECK ALL THE PLUGS, OHM'S TEST THE PLUG WIRES, CHECK DIST. CAP AND ROTOR, OR IF IT IS A COIL-PACK CHECK THE CONTACTS. MAKE SURE EVERYTHING IS PERFECT, THEN SET YOUR TIMING.
IF YOU HAVE NEVER DONE THIS, A HAYNE'S WOULD BE A GREAT INVESTMENT.
I CAN'T GARANTEE IT WILL WORK, BUT IT COULDN'T HURT.

a clean car will also get better fuel mileage, over a long enough distance as opposed to a dirty one

[2004exrider]

Awhile back the tube running off the air pump to the exhaust pipe on my truck (93 302 F-150) rusted off and now its just a horrible exhaust leak, will that make me notice quite a bit of difference in milage or is it all in my head?

Jimmy

[NorCalRacer]

I AM NOT POSITIVE I BELIEVE THAT PUMP IS THERE TO CREATE EXHAUST BACKPRESSURE AND YOU WOULD LOSE PERFORMANCE, MILAGE AND ENGINE LIFE WITHOUT REPAIRING IT. YOU MIGHT WANT TO GO JUNKYARD SURFING AND TRY TO FIND A GOOD ONE, IT WOULD PROBABLY BE WORTH YOUR TIME/$$$.
GOOD LUCK:D

[NorCalRacer]

I FORGOT TO MENTION TRANNIES
MANUAL: MOST MANUAL TRANSMISSIONS DO BETTER WITH ATF DEXRON III THAN THE RECOMMENDED 80/90 WEIGHT. TRANNIES ARE SPLASH LUBRICATED AND THE ATF GETS MORE PLACES. THIS WILL VOID WARRANTY SO DO NOT DO IT IF YOU ARE UNSURE, BUT THIS IS WHAT I RUN IN MY TRANSMISSION (85W IS RECOMMENDED) AND IT IS WHAT MOST MECHANIC SHOPS WOULD PUT IN ON A FLUID CHANGE.
AUTO: GET SERVICED EVERY 15,000 MILES. IF YOU CAN, PULL YOUR PAN AND TAP A DRAIN BOLT INTO IT SO YOU CAN DO THIS IN YOUR SHOP WITH NO MESS. IF POSSIBLE, ADD AN EXTERNAL TRANNY COOLER. THEY RUN UNDER 50$ AND WILL WORK WONDERS FOR YOUR RIDE.
A DIRTY TRANSMISSION HOLDS YOU BACK.

i use wd-40.......

[JIMTED79]

Originally posted by NorCalRacer
I FORGOT TO MENTION TRANNIES
MANUAL: MOST MANUAL TRANSMISSIONS DO BETTER WITH ATF DEXRON III THAN THE RECOMMENDED 80/90 WEIGHT. TRANNIES ARE SPLASH LUBRICATED AND THE ATF GETS MORE PLACES. THIS WILL VOID WARRANTY SO DO NOT DO IT IF YOU ARE UNSURE, BUT THIS IS WHAT I RUN IN MY TRANSMISSION (85W IS RECOMMENDED) AND IT IS WHAT MOST MECHANIC SHOPS WOULD PUT IN ON A FLUID CHANGE.
AUTO: GET SERVICED EVERY 15,000 MILES. IF YOU CAN, PULL YOUR PAN AND TAP A DRAIN BOLT INTO IT SO YOU CAN DO THIS IN YOUR SHOP WITH NO MESS. IF POSSIBLE, ADD AN EXTERNAL TRANNY COOLER. THEY RUN UNDER 50$ AND WILL WORK WONDERS FOR YOUR RIDE.
A DIRTY TRANSMISSION HOLDS YOU BACK.

This is a great thread, I am going to change my manual tranny to ATF tommarow. I serviced it with 85w weight oil when I bought it and when its cold its hard to down shift when rolling. I did not think I could put ATF in my manual tranny thanks for the info.

[MOFO]

How about removing the caps lock. Makes it VERY difficult to read.

[jiffers]

buy an old diesel run it on vegetable oil here in the UK we pay less tax on food than we do on fuel and as for the law it's a bit of a Grey area here and it smells like burgers cooking

BUT DO NOT USE IT IN A MODERN ENGINE with a high pressure fuel system (common rail) as they have very strict tolerances in the system

[LTandRaptorider]

Originally posted by MOFO
How about removing the caps lock. Makes it VERY difficult to read.

After reading his first post, my first question was...

Why is it easier for him to type in caps? :confused: :p Caps lock button broke? Hard to read small print?

Some interesting info here...

[LTandRaptorider]

Originally posted by JIMTED79
You again, he said dont read it if you dont like the caps so can you remind us why you even wrote this:grr:

Or, since he's a mod... He can just remove the thread and boot your smart-*** off of here. ;) How does that sound? :confused: :blah:

[PolarisRider06]

Originally posted by JIMTED79
I have a 94 toyota pick up with a 22re and have tryed both 87 and 91 octaine trying to see a difference and did not. Got the same mileage so I went back to 87 octaine.


that seems wierd, i've always heard that you get better mileage with higher octane... maybe for some reason toyota pickups are an exception or maybe it works better in older vehicles than that even.... i'm gonna try it in my 79 ford if i ever have the money to actually fill the tank all the way up.

[accorracer]

Originally posted by NorCalRacer
PEOPLE SEEM APPALLED BY THE PRICE OF GAS THESE DAYS. THERE ARE MANY GIMMICKS OUT TODAY: MAGNETS, TORNADOES, WATER INJECTION, ETC. MOST HAVE NO EFFECT OR NEGATIVE EFFECTS. I HAVE WORKED ON VEHICLES FOR ABOUT 10 YRS NOW AND HERE ARE SOME METHODS THAT GURANTEED WORK. BTW, IT IS EASIER FOR ME TO TYPE IN CAPS SO IF YOU DON'T LIKE CAPS DON'T READ THIS PLEASE, I DON'T WANT TO WASTE MY TIME TALKING ABOUT MY TYPING, THIS IS TO HELP PEOPLE.

1: PREMIUM GAS. IF YOU HAVE AN OLDER VEHICLE CHANCES ARE THE GAS WAS A LOT BETTER WHEN IT WAS MADE. MORE OFTEN THAN NOT, YOUR DOLLAR WILL GO FURTHER WITH THE BETTER GAS.

2: SMOG, VACUUM SYSTEM. WHETHER CARBURETED OR INJECTED, ALMOST ALL VEHICLES HAVE SOME FORM OF VACUUM/ SMOG SYSTEM RUNNING ON THE MOTOR. IF YOUR MOTOR DOESN'T WARM UP PROPERLY OR IF ANY OF THE SMOG UNITS (EGR VALVE. AIR PUMP, CHECK VALVES, O2 SENSOR ETC) AREN'T FUNCTIONING PERFECTLY YOUR MILEAGE WILL REALLY SUFFER.

3: ELECTRIC FAN. IF YOUR VEHICLE ISN'T ALREADY EQUIPPED WITH ONE, INSTALL A THERMOSTATICALLY CONTROLLED ELECTRIC FAN. THESE ARE EASY TO INSTALL, COST ABOUT $200 AND FREE UP A SIGNIFIGANT AMOUNT OF HORSEPOWER MAKING YOUR ENGINE NOT HAVE TO WORK AS HARD.

4: EXHAUST LEAKS. A BAD EXHAUST LEAK WILL TAKE BACKPRESSURE OFF YOUR ENGINE AND MAKE IT RUN IMPROPERLY.

5: AIR CLEANER AND SPARK PLUGS OBVIOUSLY

6: SUSPENSION/TIRE PRESSURE. A SOFT SUSPENSION WILL ROB POWER MAKING YOUR ENGINE WORK HARDER.

7: OIL. DIRTY OIL ROBS GAS MILEAGE AND KILLS YOUR ENGINE. CHANGE EVERY 3000 MILES.

I HAVE A FULL SIZED CHEVY TRUCK WITH A 4.3 L V-6 IN IT AND I ALMOST GET THIRTY MILES TO THE GALLON. I THINK PEOPLE WOULD BE AMAZED THE MILEAGE THEY COULD GET OUT OF A VEHICLE THEY ALREADY OWN INSTEAD OF BUYING A NEW ONE.

IF ANYONE ELSE KNOWS SOME TRICKS PLEASE POST THEM HERE, I WOULD LIKE TO TRY THEM OUT.


i'm a long time mechanic too and i seriously fail to see how dirty oil will rob any gas milage? unless you just have never changed it and the motor is sludge damaged but even then i seriously doubt you will feel any fuel milage difference. i think your more likely to blow up the motor than see a decrease in fuel milage,

premeium gas burns cleaner, faster and in most cases will reduce mileage because it burns faster and cleaner.

and if your claiming 30mpg on a 4.3 v6 fullsize truck i think your full of b.s. i know better than that. i don't care if you never push the accelerator more than a 1/4 of the way down. you will never get 30mpg. i think your tripometer is off.

[NorCalRacer]

THAT IS MY FREEWAY MILEAGE. I AM FULL OF NOTHING. I BUILT MY MOTOR FROM THE GROUND UP AND THAT IS WHAT I GET, NO BS. I DON'T CARE WHAT YOU THINK. HAVE A NICE DAY:D

[pastfast125]

IMHO, if you have a fullsize motor ( a.k.a V8 Mans Motor, lol) Then You don't want back pressure, you want veloctiy. Now ON the smaller motors like the 4.3 v6, you still don't need back pressure, but running an open exhaust on the older years, like my s10, will clog up the EGR setup, but if you clean it occasioanally, it's not a problem.

[WheelieMan4]

I have a 93 Dodge Dakota 5-speed. And I get the worst gas mileage that I have ever seen...Would putting 93 in help? Or what else, I know when I really get on it thats not good...but I dont do that very often. So what would you reccomend for me? Thanks alot!! Would really like to save some money!!

[NorCalRacer]

I would try better gas and see what happens. If it doesn't help, try checking out a shop manual like a Hayne's or Chiltons and troubleshoot your emissions system. Start simple, make sure it is running warm enough and your thermostat is opening at the specified temperature for your vehicle and make sure your oxygen sensor is functioning properly. After that, I am not sure the exact setup of your emissions system you can usually check everything on them with a multimeter and a hand held vacuum pump. If you don't have these tools they are inexpensive and most of the time parts store have a set they will rent or loan out.
A shop manual is always a good investment. PM me if you have another question.
Good Luck:D

[mxdave28]

if you have a truck the biggest and easiest thing you can do to increase milage is to put a bed cover on it....soft or hard doesnt matter just cover it.....oh and by the way putting the tailgate down DO NOT WORK!!! it does not give you better milage so dont bother

[Warnerade]

Originally posted by mxdave28
if you have a truck the biggest and easiest thing you can do to increase milage is to put a bed cover on it....soft or hard doesnt matter just cover it.....oh and by the way putting the tailgate down DO NOT WORK!!! it does not give you better milage so dont bother on smaller trucks...it works, but on newer full size trucks...it doesnt make a difference.


btw..norcal

[MOFO]

I have cleaned this thread up. JIMTED79, knock off the attacks!

[underpowered]

Originally posted by accorracer
i'm a long time mechanic too and i seriously fail to see how dirty oil will rob any gas milage? unless you just have never changed it and the motor is sludge damaged but even then i seriously doubt you will feel any fuel milage difference. i think your more likely to blow up the motor than see a decrease in fuel milage,

premeium gas burns cleaner, faster and in most cases will reduce mileage because it burns faster and cleaner.

and if your claiming 30mpg on a 4.3 v6 fullsize truck i think your full of b.s. i know better than that. i don't care if you never push the accelerator more than a 1/4 of the way down. you will never get 30mpg. i think your tripometer is off.

i agree about changing oil. You will not see an increase just by changing oil.

But for the gas, It works to run a higher octane But ONLY if you vehicler was built to run off that octane. most of todays vehicles. are built to run off 87, anything higher is a waste of money, and if it does increase your milage, very rarely is it enough to offset the extra cost of the higher octane. starting in the mid 80's, vehicles were made to run off of the cheap stuff.
Other fuel milage tricks:

Take it easy on the skinny pedal, drive as if there is an egg on it, accelerlate slowly.

in an auto tranny, dont force downshifts on uphill grades.

Cruise control is your friend, Use it! the computer in you car knows best on how much throttle is needed at a certain speed.

Believe it or not, but you need to blow it out every now and then. drive easy most of teh time, but i have found that actually running it though the gears once in a while will help. i tached out my truck atleast once per tank, and if i did not, i would actually see a slight loss in MPG.

Air pressure is important, find out what works best for you.

like norcal said, Nothin beats a good tune up.

[NorCalRacer]

When I say dirty oil can hold you back I don't mean a 3000 miles, or even 5000. In my neighborhood it is common for people to go 10,000 miles before an oil change at which point their oil resembles wheel bearing grease to some degree and has lost most of it's beneficial properties. I say every 3000 because it is a good habit.
Good tip on the tranny and knocking the carbon out of your engine. I believe it is important to "get on it" at least once a week to keep the engine running perfect, it cleans everything.
Thanks for the input

[450RGNCC]

EVERY engine needs backpressure, i dont care what engine you show me, you MUST have backpressure for it to run properly. Stock engines can have more backpressure because there is not a whole lot of flow, but with more modification, you can have less backpressure because you will have more flow. And the purpose of an air pump is to introduce fresh air to the exhaust system so that your cats will burn hotter, in turn burning off more NOx and CO, and reducing emissions. And yes I am a certified Emissions inspector (even though I am not 18, but they I will receive my liscense the day I turn 18).

[NorCalRacer]

Thanks, you're correct. I know on my truck, the air pump will create a drop in exhaust backpressure if it malfunctions but that could be unique to my vehicle. I think you are correct on it's main purpose although I am not a smog tech just a backyard wrencher. Thanks for the input and good luck with your career. Sound's like your going to do well.

[honda350r]

[QUOTE]Originally posted by accorracer
[B]i'm a long time mechanic
premeium gas burns cleaner, faster and in most cases will reduce mileage because it burns faster and cleaner.

Your a long time mechanic and you think higher octane burns faster than low octane ? :rolleyes:

[Rich250RRacer]

Originally posted by accorracer
i'm a long time mechanic too and i seriously fail to see how dirty oil will rob any gas milage? unless you just have never changed it and the motor is sludge damaged but even then i seriously doubt you will feel any fuel milage difference. i think your more likely to blow up the motor than see a decrease in fuel milage,

premeium gas burns cleaner, faster and in most cases will reduce mileage because it burns faster and cleaner.

and if your claiming 30mpg on a 4.3 v6 fullsize truck i think your full of b.s. i know better than that. i don't care if you never push the accelerator more than a 1/4 of the way down. you will never get 30mpg. i think your tripometer is off.

Maybe you don't know as much as you think. I drove my 1990 C1500 with a 4.3 and 90000 miles on it to the Loretta Lynn's GNCC a few years back. I fueled up at home in Youngstown, Ohio and drove straight to Nashville which was 587 miles. I topped the tank off there and it took 21.5 gallons of gas. You do the math, know-it-all. Not quite thirty, but damn good gas mileage for a truck that was almost ten years old at the time, and loaded down with my quad, tires and gear.

[pastfast125]

About the backpressure thing..umm, tell me why my friend with a big block has open headers, and it runs amazing, and on my chevy 350 open headers run fine. And same as on my s10, with an X pipe on my s10 4.3 I can run open headers no problem, all it is is the EGR has to be cleaned occasionally. Yes sometimes an o2 simulater is needed, but don't tell me it needs back pressure, cuz it's BS.

[450RGNCC]

Well, headers= backpressure. Go run a car with no headers and tell me how it runs. I bet that your 350 and your buddies big block both have modifications done to your intakes. Once again, EVERY ENGINE NEEDS BACKPRESSURE. You think that open headers is no backpressure, but you are totally wrong. Take the silencer off of your atv or dirtbike and just leave the headpipe on, and tell me how it runs.

[pastfast125]

we're not talkin about quads here bud. Small motors like that react differently to changes. and um no, my 350 has no intake mods, in fact it has no motor mods whatsoever. Not even a high flow filter. Even if headers do cause back pressure, it's a miniscule(sp) amount. So you're telling me that the mud bog trucks that run pipes striaght out the hood dont run? Is it a figment of my imagination that I'm seeing them blast across the feilds and mud holes?

[JIMTED79]

I thought that back pressure created torq? and headers are a vital part that creats the back pressure?

[pastfast125]

velocity produces power

[JIMTED79]

But dont you have to get the pistons turning hard to create velocity? where does the torq come from then?

[pastfast125]

well combustion in the engine turns the pistons, the exhaust doesnt push the pistons, When u crank the engine, whn the pistons move down it creates suction, pulls the air/fuel misture in, then the upwards stroke combusts it, and it is ignited, pushing the piston back down, blah blah, continues the cycle. With back pressure IMO it's only making it harder for the motor to push the exhaust gases out, therefore robbing power. With more velocity, and no back pressure, the exhaust gases flow out quickly and easily, which makes the motor not work as hard to push it out.

[harescrambles]

Originally posted by honda350r
[QUOTE]Originally posted by accorracer
[B]i'm a long time mechanic
premeium gas burns cleaner, faster and in most cases will reduce mileage because it burns faster and cleaner.

Your a long time mechanic and you think higher octane burns faster than low octane ? :rolleyes:



Actually he is right, higher octane burns faster and cleaner.

[Warnerade]

Originally posted by pastfast125
we're not talkin about quads here bud. Small motors like that react differently to changes. and um no, my 350 has no intake mods, in fact it has no motor mods whatsoever. Not even a high flow filter. Even if headers do cause back pressure, it's a miniscule(sp) amount. So you're telling me that the mud bog trucks that run pipes striaght out the hood dont run? Is it a figment of my imagination that I'm seeing them blast across the feilds and mud holes? go pull your headers off..run your engine with the exhaust coming straight out of the manifold...then come back and tell us how good it runs.

[450RGNCC]

The last time that I looked, a 4 stroke atv engine and a 4 stroke car engine work EXACTLY the same way, and all of the principles for the exhaust and backpressure will be EXACTLY the same. And headers do create more back pressure than you think. Do what NacsRacer027 said and go pull of your headers. If you are trying to say that the less back pressure the better, than your engine should run REALLY WELL without any headers at all, right? So you go run open exhaust ports and let all of us know how that works out.

i ran my dr500 dirtbike without a header

[Honda TRX250ex]

Originally posted by 89honda 250x
i ran my dr500 dirtbike without a header
what the hell is wrong with you?
did you fall out of a stupid tree and hit every branch?

[jonc623]

Originally posted by accorracer
i'm a long time mechanic too and i seriously fail to see how dirty oil will rob any gas milage? unless you just have never changed it and the motor is sludge damaged but even then i seriously doubt you will feel any fuel milage difference. i think your more likely to blow up the motor than see a decrease in fuel milage,

premeium gas burns cleaner, faster and in most cases will reduce mileage because it burns faster and cleaner.

and if your claiming 30mpg on a 4.3 v6 fullsize truck i think your full of b.s. i know better than that. i don't care if you never push the accelerator more than a 1/4 of the way down. you will never get 30mpg. i think your tripometer is off.


last i knew higher octane gas burns slower and cooler than low octane

[Warnerade]

Originally posted by jonc623
last i knew higher octane gas burns slower and cooler than low octane the last thing you knew was wrong.

[Fred55]

The higher the octane...the hotter the gas can get before it detonates.

[pastfast125]

Originally posted by NacsRacer027
go pull your headers off..run your engine with the exhaust coming straight out of the manifold...then come back and tell us how good it runs.

No, That doesn't provide the velocity. The headers are needed to provide the right velocity, to pull the exhaust gases away from the motor. Without the headers, there is nothing pulling the gases away, they just exit right there.

[pastfast125]

oh BTW, click on the link that says " see a video of the engine running right out of the box"

http://www.enginefactory.com/

[pastfast125]

thanks captain, but that wasnt the arguement;)

[JIMTED79]

Originally posted by harescrambles
Actually he is right, higher octane burns faster and cleaner.

You only need as much octane as it takes to resist pre ignition and detonation. So the lower octane ignites faster and the higher the octane ignites slower to resist pre ignition and detonation.

[Toadz400]

pastfast125 you have to be extremely stupid to think an engine doesn't need torque. Go put dual 10" straight pipes on your 350 and see how it runs. Ever heard of "Ricers"? Obnoxious cars that have 3" pipes that sound like farts? Sad thing is, farts are faster :ermm: .

Oh, and higher octane does not increase gas mileage. And yes it does run cooler.

[pastfast125]

Originally posted by Toadz400
pastfast125 you have to be extremely stupid to think an engine doesn't need torque. Go put dual 10" straight pipes on your 350 and see how it runs. Ever heard of "Ricers"? Obnoxious cars that have 3" pipes that sound like farts? Sad thing is, farts are faster :ermm: .

Oh, and higher octane does not increase gas mileage. And yes it does run cooler.

Can you not read? Where were we talking about torque? Oh, and notice how I stated velocity like 10 times? !0" pipes will provide no velocity. A well designed exhaust with 2.5" piping, will provide the velocity, and efficiantly draw the exhaust gases from the motor. Would you like me to get a bunch of quotes from people from a dediacted truck forum who agree with me? Or maybe we should rely on you, although you can't read, your probably right:rolleyes:

[Toadz400]

Originally posted by pastfast125
Can you not read? Where were we talking about torque? Oh, and notice how I stated velocity like 10 times? !0" pipes will provide no velocity. A well designed exhaust with 2.5" piping, will provide the velocity, and efficiantly draw the exhaust gases from the motor. Would you like me to get a bunch of quotes from people from a dediacted truck forum who agree with me? Or maybe we should rely on you, although you can't read, your probably right:rolleyes:

You and JIMTED79 were talking about torque, and you believe that backpressure is not needed in any engine bigger than a 4 cylinder.
V6's and V8's are all about torque, and backpressure has a lot to do with available torque, but I know not everything. You want backpressure to have an efficient vehicle, in NASCAR where they try to have as little backpressure as possible I don't think they are worried about what their gas mileage is.

I guess what we should really be arguing about is what you are going to be using the engine for. If you are running it WOT in the same gear then yes, less backpressure would benefit you.

Want to know what happens when you reduce backpressure without addressing other parts of the engine?
# A degree of cylinder pressure will be lost (a decrease in available torque)
# Effective air/fuel mixtures will be leaner (possibly leading to parts damage).
# Ignition spark requirements will change.
# The exhaust system's temperature will rise (owing to the burning of air/fuel mixtures in the exhaust manifolding and pipes).
# Exhaust gas temperatures will increase (particularly notable during engine dynamometer tests).
# There will be a tendency of back-fire (or popping) during deceleration of the engine.

[PolarisRider06]

HIGHER OCTANE= more solid, cleaner burn, prevents detonation, allows use of higher compression which in turn creates horsepower, in some cases help mileage esspecially in older vehicles(pre 80's) when the gas was better.

headers MAY create backpressure but do you really think that those mudrunners with zoomies or race cars with drag headers and no mufflers have backpressure? no they do not, the header tubes are bigger than the exhaust ports to kill backpressuer then they are portmatched to the heads to promote a smoother faster flow.

engines do not NEED backpressure to run, if you know how to tune the engine(ie jetting/carb settings) or if its fuel injection it will do it for you. did you know that earlier 90's ford f-150's with 302's run less than a pound of backpressure in manny cases and thats with stock exhaust? thats for the performance.... i've seen the tests done in person and the results, i worked in an auto shop for 2 years for my uncles. no backpressure will increase horsepower more in some cases than others and slightly lower the torque, that also depends on the situation.

if you dont have any backpressure you will burn out valves faster because the exhaust gasses can get away from the engine faster because there is nothing holding them back which means the exhaust doesn't draw off as much heat from the engine as it does when there is backpressure (yes exhaust does help to cool the engine, specifically the valves)

all of this was explained and shown to me by the mechanic at my uncles shop who is ASE certified for diagnostics, mechanics, engine performance, heating/cooling systems and some other stuff. he has built his share of performance vehicles and is your standard motorhead with a better knowledge than a standard motorhead.

[450RGNCC]

Originally posted by pastfast125
No, That doesn't provide the velocity. The headers are needed to provide the right velocity, to pull the exhaust gases away from the motor. Without the headers, there is nothing pulling the gases away, they just exit right there.

lol, wow. you obviously have absolutely no idea what you are talking about. Tell me how headers "pull" the gases away????

There are 2 reasons for headers:
1.) BACKPRESSURE
2.) TO DIRECT THE GASES IN WHATEVER DIRECTION THEY NEED TO BE DIRECTED

Velocity is created through the intake and intake ports. The exhaust port must be able to flow the gases smoothly, but the headers are for the backpressure. Headers have NOTHING to do with velocity, the only way that they can affect velocity is if they are too restrictive and they do not allow gases to exit the combustion chamber, so that there are gases left in the chamber, which would not allow as much of the intake charge to enter, but that would only happen if the exhaust was VERY restrictive. Go hold your hand most of the way over your exhaust pipe while your bike is running and you will see what I am saying.

[honda350r]

This thread has more bull***** in it than any other thread on this site !

T

[JIMTED79]

Originally posted by honda350r
This thread has more bull***** in it than any other thread on this site !

T
What do you mean? this is a good debate.

[pastfast125]

Originally posted by Toadz400
You and JIMTED79 were talking about torque, and you believe that backpressure is not needed in any engine bigger than a 4 cylinder.
V6's and V8's are all about torque, and backpressure has a lot to do with available torque, but I know not everything. You want backpressure to have an efficient vehicle, in NASCAR where they try to have as little backpressure as possible I don't think they are worried about what their gas mileage is.

I guess what we should really be arguing about is what you are going to be using the engine for. If you are running it WOT in the same gear then yes, less backpressure would benefit you.

Want to know what happens when you reduce backpressure without addressing other parts of the engine?
# A degree of cylinder pressure will be lost (a decrease in available torque)
# Effective air/fuel mixtures will be leaner (possibly leading to parts damage).
# Ignition spark requirements will change.
# The exhaust system's temperature will rise (owing to the burning of air/fuel mixtures in the exhaust manifolding and pipes).
# Exhaust gas temperatures will increase (particularly notable during engine dynamometer tests).
# There will be a tendency of back-fire (or popping) during deceleration of the engine.

Yea, you made a good point there, it depends on what the engine will be used for, but it's just not true that engines need back pressure.


Oh, and yes, the exhaust system does have a big effect on the velocty, if you don't have a well designed exhaust system or headers, where it is blocking up the gases, your obviously reducing the velocity, and not pulling the gases away from the motor. Oh, and NO CHIT, the motor isn't gonna run right without matching fuel system changes, as well as computer if it's efi and all the other involved changes.

[pastfast125]

Originally posted by honda350r
This thread has more bull***** in it than any other thread on this site !

T

my bad, I guess I missed the abundance of intelligent posts you must have contributed to this thread:rolleyes:

is that all you do? Post whore and complain?:confused: :ermm:

[honda350r]

Originally posted by 450RGNCC
lol, wow. you obviously have absolutely no idea what you are talking about. Tell me how headers "pull" the gases away????

There are 2 reasons for headers:
1.) BACKPRESSURE
2.) TO DIRECT THE GASES IN WHATEVER DIRECTION THEY NEED TO BE DIRECTED

Velocity is created through the intake and intake ports. The exhaust port must be able to flow the gases smoothly, but the headers are for the backpressure. Headers have NOTHING to do with velocity, the only way that they can affect velocity is if they are too restrictive and they do not allow gases to exit the combustion chamber, so that there are gases left in the chamber, which would not allow as much of the intake charge to enter, but that would only happen if the exhaust was VERY restrictive. Go hold your hand most of the way over your exhaust pipe while your bike is running and you will see what I am saying.

Engine basics teach us that an engine is nothing more than an air pump, the more air we put into the engine the more air must come out. Today's smaller high flowing intake ports require a high flowing exhaust port that can expel the spent gasses, which proves that it requires a certain amount of volume and flow to produce a certain amount of power. This same general rule of thumb can be used to dictate the size of the primary tube required to make a certain amount of power on a competition engine.

As previously stated, Performance Welding feels its best to use as small of a primary tube possible for your particular application, just as with the collector sizing.

Every Competition Engine does, although have its own inherit characteristics. Some engines use a small high flowing intake and exhaust port and some use a large high flowing port. Some classes require a stock intake port, and to obtain high volumetric effiency with the engine, excessive camshaft overlap and duration is required to help the competition header pull air through the engine, as the low flowing stock cylinder head cant perform this feat on its own.

Headers can and do pull the exhaust out of a engine!

[pastfast125]

there wo go, Thanks you!:p

[JIMTED79]

Originally posted by honda350r
Engine basics teach us that an engine is nothing more than an air pump, the more air we put into the engine the more air must come out. Today's smaller high flowing intake ports require a high flowing exhaust port that can expel the spent gasses, which proves that it requires a certain amount of volume and flow to produce a certain amount of power. This same general rule of thumb can be used to dictate the size of the primary tube required to make a certain amount of power on a competition engine.

As previously stated, Performance Welding feels its best to use as small of a primary tube possible for your particular application, just as with the collector sizing.

Every Competition Engine does, although have its own inherit characteristics. Some engines use a small high flowing intake and exhaust port and some use a large high flowing port. Some classes require a stock intake port, and to obtain high volumetric effiency with the engine, excessive camshaft overlap and duration is required to help the competition header pull air through the engine, as the low flowing stock cylinder head cant perform this feat on its own.

Headers can and do pull the exhaust out of a engine! Ok so for smaller intake and exhaust ports to make good power you need the overlap and duration on the cam or cams to be higher therefore the valves stay open longer. So the valves stay open longer for the piston to push all the spent gases out of the exhaust port. You said that its best to use a small primary tube, would that not create back pressure?

[450RGNCC]

Originally posted by JIMTED79
Ok so for smaller intake and exhaust ports to make good power you need the overlap and duration on the cam or cams to be higher therefore the valves stay open longer. So the valves stay open longer for the piston to push all the spent gases out of the exhaust port. You said that its best to use a small primary tube, would that not create back pressure?
thank YOU!

[pastfast125]

no, with the right size tubing, and if it's designed right, it doesn't creat back pressure, but it actuall pulls the exhaust gasses. Yes, if you get too small, I could see that creating back rpessure, but the diameter of the pipe needs to be matched to the motor and the porting and all that.

[AtvMxRider]

Well after reading this whole thread( a waste of 5 minutes of my life) I have come to the conclusion that this site is full of dumb *** people. Half you people have no idea what your talking about.:rolleyes:

[PismoLocal]

I just insatlled a flex-a-lite fan on my toyota tacoma and it is supposed to give better fuel economy and horse power we will see how it goes though. I can totally feel the extra horse power so i couldnt imagine the added gas mileage not being there.

[Warnerade]

Originally posted by AtvMxRider
Well after reading this whole thread( a waste of 5 minutes of my life) I have come to the conclusion that this site is full of dumb *** people. Half you people have no idea what your talking about.:rolleyes: ok so enlighten everyone here jerry...tell everyone in this thread the truth about headers...and everything else you disagree with...I'm dying to hear it.

[pastfast125]

Originally posted by NacsRacer027
ok so enlighten everyone here jerry...tell everyone in this thread the truth about headers...and everything else you disagree with...I'm dying to hear it.

agreed, I hate when people come in and flame about how dumb people are, but yet have no imput of their own.:rolleyes:

[JIMTED79]

Originally posted by pastfast125
agreed, I hate when people come in and flame about how dumb people are, but yet have no imput of their own.:rolleyes:

I hear that, can't stand that chit!!!

[pastfast125]

all in all though, the starter of this thread made some good points for helping your engine run better, increasing the life of your engine and drivetrain oparts, adn getting better gas mileage...good job man;)

[Toadz400]

Originally posted by pastfast125
all in all though, the starter of this thread made some good points for helping your engine run better, increasing the life of your engine and drivetrain oparts, adn getting better gas mileage...good job man;)

Yea I have to agree with most of that. Some things I don't really see doing anything, especially the premium (unless in older vehicles, I guess I could understand that).

[Rootar]

WOOOW after reading this whole thread i found 2 people to actaully understand the idea of higher octane in fuel, did yall never have Chemistry in school?

Higher octane changes one thing in fuel.........how hot it burns, 91 WILL burn hotter creating more pressure inthe combustion of the stroke therefore creating more power, why do you think high compression motors need such hihg octane levels to reach there potential? 87 doesnt provide the heat needed.......but as for a gas mileage increase it shouldnt be noticable but the power is definetly noticable if your running performance mods in and older motor.

dont even begin to question me on this i know what im talking about hows making a 5 (highest possible score, only achived by less than 10 people in the whole country this year) on the AP chemistry test and recieving full 6 hour credit in chemistry to any college i attend when i graduate next year.






Norcal your exactly right man

very key things are tire pressure and routine maintenence and knowing how to drive

i run my tires at max Cold PSI they are check twice a week

change your oil, clean your air filter and rotate your tires every 3,000 miles (i gained 2 mpg by switching to an FP2K air filter system)

driving correctly--well there is alot to tell, main things to remember, take off easy dont floor it, when your going down a hill if its flat at the bottom let off and coast easily giving it gas agian----if it goes up after the bottom slightly gain speed going down the hill so that your car or truck's momentum will make it easier on the motor to make it up the hill, Dont drive 70 and 80 mph on and off the gas alot drive right at 60 mph with a steady pedal (mopst all vehicles are geared to get optimal mileage at 60mph), when your going to stop let off the gas far enough away that you coast as much as you can (saves gas and brakes).


i drive an 04 F-150 heritage with the auto V-6 and i can honestly say that i get 24.2 mpg maybe its becasue i care if i waste my money on simple corrections that can be made with no effort.

[Toadz400]

Originally posted by Rootar
WOOOW after reading this whole thread i found 2 people to actaully understand the idea of higher octane in fuel, did yall never have Chemistry in school?

Higher octane changes one thing in fuel.........how hot it burns, 91 WILL burn hotter creating more pressure inthe combustion of the stroke therefore creating more power, why do you think high compression motors need such hihg octane levels to reach there potential? 87 doesnt provide the heat needed.......but as for a gas mileage increase it shouldnt be noticable but the power is definetly noticable if your running performance mods in and older motor.

dont even begin to question me on this i know what im talking about hows making a 5 (highest possible score, only achived by less than 10 people in the whole country this year) on the AP chemistry test and recieving full 6 hour credit in chemistry to any college i attend when i graduate next year.

So why is it that the engine pre-detonates and runs hotter in a high compression engine when using regular fuel?

[PolarisRider06]

LMAO.... calling out the chemistry wizz.... Rootar is thinking like engineers... all in a perfect world.... in the right conditions, wait let me rephrase that in the PERFECT conditions, he is completely right.... now lets see your chemistry explain the pre detonating like Toadz asked about.... i can explain that one quite easilly, but i want to hear the chemics perfect world explanation....


now on the idea of oil changes not improving gas mileage(sorry i'm bringing up posts from quite a while ago) it actually does.... the oil in your engine does three main things, lubricate, clean and cool. and when the oil starts to break down it doesn't have as good of cooling efficency, if the engine runs hotter that puts more load on the cooling system which robs more power which decreases mileage.... (just figured i'd throw that nice little bit of information out there)


oh and the other night while cleaning my truck i thought of one other fuel saver.... keep your engine clean, wash off the dirt mud and grease off and on because a clean engine runs cooler (just like on quads) and thats back to reducing stress on your cooling system and saving power in turn saving gas.

[NorCalRacer]

Thanks for the tip. Also, make sure it warms up. If your thermostat is lower than stock or stuck open it could kill your fuel efficiency. This is more true with fuel injected, some old carbureted motors even might do better cooler. I am sure there are exceptions to this like everything else but it is a good thing to watch for.

[PolarisRider06]

if you have an older vehicle this will apply more than on most newer vehicles.... make sure all your vacuum lines are connected and in the right place.... i'm not one to preach about it because i know they're all F'ed up on my 79 ford but i know if i could somehow figure it all out it would greatly help my mileage.

[pastfast125]

I have a question tha tI know nothing about. On my k1500, it has the stock 350, well the vaccum hoses are capped off, what exactly does that do? :confused:

[NorCalRacer]

It is so you don't leak vacuum, that would make your engine run poorly or not at all. I would try to find where they go if possible. Probably no harm done except possibly a little performace loss.

[Rootar]

Originally posted by Toadz400
So why is it that the engine pre-detonates and runs hotter in a high compression engine when using regular fuel?


i was just telling how its supposed to work toadz :o

why is it that when i ran a 13:1 comp in my 416 for like 2months and it wouldnt run for shat on regular and when on 50/50 Half race gas it just purrrrrrrd ,,,,, i dunno how everything works man but i know that JUST the OCTANE amount changes one thing we did alot with fuel and fuel consumption and the affects and engergy put off in my chem class..... thats all i know

[Rootar]

Originally posted by PolarisRider06
LMAO.... calling out the chemistry wizz.... Rootar is thinking like engineers... all in a perfect world.... in the right conditions, wait let me rephrase that in the PERFECT conditions, he is completely right.... now lets see your chemistry explain the pre detonating like Toadz asked about.... i can explain that one quite easilly, but i want to hear the chemics perfect world explanation....


now on the idea of oil changes not improving gas mileage(sorry i'm bringing up posts from quite a while ago) it actually does.... the oil in your engine does three main things, lubricate, clean and cool. and when the oil starts to break down it doesn't have as good of cooling efficency, if the engine runs hotter that puts more load on the cooling system which robs more power which decreases mileage.... (just figured i'd throw that nice little bit of information out there)


oh and the other night while cleaning my truck i thought of one other fuel saver.... keep your engine clean, wash off the dirt mud and grease off and on because a clean engine runs cooler (just like on quads) and thats back to reducing stress on your cooling system and saving power in turn saving gas.




and yes we did our experiments in "perfect conditions" i was just stateing what the ACTUAL octane did in the fuel, the fuel make up has to many variables.. but yes i guess i might be only right in "perfect conditions"......oh well no need to argue not like it matters




:confused:

[Racing Rice]

You want better gas mileage.. Buy a motorcycle. My VStrom gets +55 mpg and has a 5.8 gallon tank and still capable of running 12s in the quarter mile.. :)

[PolarisRider06]

Originally posted by Rootar
and yes we did our experiments in "perfect conditions" i was just stateing what the ACTUAL octane did in the fuel, the fuel make up has to many variables.. but yes i guess i might be only right in "perfect conditions"......oh well no need to argue not like it matters




:confused:


yeah i figured it was a perfect conditions thing.... me and my dad always get in conversations about the engineers that he has worked with that say something cant be done and then he proves them wrong.... lol....

nah theres no need to argue about it its just kinda one of them little things you know... a good engineer or scientist for that matter will pick up on things how they work in the real world and incorporate them into their work.

just outta curiousity is there any "scientific" explanation to the predetonation of lower octane gas or do you just know it like i do, that the air in the intake ports heats the gasses and then the cylinder temperatures are to hot (normally due to increased compression which raises the cylinder temp... just think diesel) for the lower octane gas (which ignites easier at lower temperatures) and causes it to ignite before the actual ignition system is supposed to ignite it....

[preacherboy]

I have enjoyed the information here but i have another question, I was in a hit and run the other day...My insurance is not going to cover it because i just have liability. I have a 93 Camry and i thought it was just cosmetic damage. But i took all the broken fender and bumper off and i drove it around the block and i shifts hard now. (it is an automatic) around the same time i smelled exhaust. There was a separation in the pipe and the cad. converter. Will this exhaust leak cause the engine to run rough?

Thanks!

[hondajoe05]

i have a 1990 dodge dakota 3.9 ext. cab 2wd with 1 straight pipe 270,000 miles on it change the plugs about every 3 months i only get 8 miles a gallon why? im only running 25inch tires too

[HondaEXrider22]

But higher octane fuel burns hotter, correct? Doesnt that mean it burns faster, also?