87 vs 93 octane

[Martin Blair]

if i buy 93 octane instead of 87 what would be the benifits? the engine doesnt ping with 87 but would it ahve any more power? thanks.

[Natertot426ex]

The higher octane helps the motor out a lot. I don't know how but that is what I have been told.

[proquad_20]

I COPIED THIS FROM SOMWHERE ELSE, BUT IT SHOULD SHED SOME LIGHT ON YOUR QUESTION....

Octain rating is a measurment of how fast the fuel will burn.

Note: feul can be ingnited by heat"spark" and pressure"compression"

It's a balance game, a motor built for a low octain fuel has a lower compression ratio and will develope less horse power becouse of it. If the compression is raised when the spark plug fires the initial burn pressure will cause all the feul to burn all at once "like a diesel motor" and that is that ping noise you here on acceleration. Becouse it burnt all at once you will experience a power loss "The ideal burn will happen for the entire stroke of the pistion". So to keep it form burning all at once they raise the octain of the feul "that makes it less volitable so it takes more pressure for it to ignite"
In the mid 70's they figured out if they inject a little exhaust in with the initail mixture "pollute the mixture" using a device called a EGR Valve "Exhaust Gas Resurculation" it would cause the mixture to be less volitable thus giving the same result of a higher octain feul. Prior to the 70's they controlled it by adding Lead to the feul "leaded gasoline" by adding lead it also slowed the burn down.

So to determin what octain you should use will take trial and error. This hold true mostly for older cars becouse almost all the new ones control the motor to adjust automaticly for any octain.

Start with the lowest octain... If you experience "pinging" and loss of power on a hard acceleration you will need to move up to a higher octain.

There are other variables that applie also. Motor Timing is one, you can retard the timing thus causing the burn to begin at a lower compression ratio "when the piston is on it's way down already" but this will cause a loss of power so it's a trade off.

[racerx573]

115 octane :D

i just use 89 on my 400ex....seems to work good, i'd like to know though if I should be using 89 or not, could it mess up my engine in the long run?

[4TraxRider]

As long as you don't do anything that will produce more compression you should be alright. But it would be better for your EX to run on 93.

[Sprttrx400ex]

I always run 93 octane, burns cleaner. I had some problems with running 87 and 89 before in my 300ex, so when I got my 400ex I just ran the 93, and it works great. :devil

[proquad_20]

i used 93 until i took my motor apart and saw what it left behind, nasssy 110 at least for me please

what about those bottles of gas boost? You can get them at wal-mart & stuff. They are in like red bottles & are supposed to be mixed with like 5 gallons or more? Has anyone used these? are they good on four wheelers? Im gonna start running 93 now.

[northeast400]

mine seems to like VP 110 leaded

[lex luger]

Originally posted by HN400exracer
the engine doesnt ping with 87 but would it ahve any more power? thanks.


higher octane will make it run cooler, it will ping with 87, its possible to ping even with 93.....alcohol on the other hand
:muscle:

[Varmit57]

First off remember this - Higher octaine = less Horse power!!

If you don't want to spend the money on race fuel like VP or Senoco then run the lowest octaine that you can without your motor ping.

But as Sprttrx400ex and proquad_20 the higher octane fuels burn cleaner, but it is not from the octaine it is becuse that fuel is better quality. that is why you pay more at the pump.

The Octaine boost stuff that you get at Walmart is a waste of money and will only rob you of power!

Most motor builders will recomend running 110 race fuel even on stock motors! Not becuse of the octain, but becuse of all the other additives in it that more then make up for the power loss that from the high octaine.

[heavy_d]

Torco 110, but i use 93 in my quadsport and sometimes 4 oz of octane booster because the whole bottle treats 20 gallons and it noticeably runs better and revs better and gets rid of any weird noises