Penzoil???

[SnowFlake]

Is penzoil 10w-40 good for my 400ex?

[NacsMXer]

It will do, but it certainly is not a high quality oil that will protect your motor better for longer periods. I use that stuff when I break-in a fresh motor for the first time, then I switch back to the synthetic good stuff..:D

You can tell that I am biased to synthetics, hey who isn't who has used it before? :blah: But that 10w40 shouldn't hurt it, just change the oil more frequently b/c that stuff breaks down pretty quickly.

[SnowFlake]

Ok last time im using penzoil then

[2muchquad]

i personally like regular oil,i have never been a fan of the artificial stuff.as long as you change your oil regularly pennzoil etc will work.no need to spend $10 a qt for the synthetic stuff that should be changed frequently as well,regardless of what you heard.:)

[bwamos]

The penzoil mos likley is a blend that has polymers in it that will cause your clutch to slip prematurely. No matter what brand you get (penzoil is among the worst), you need an oil that is safe for a wet clutch.

I prefer and reccomend AMSOIL ATV 0w40 for average ATV's, and 20w50 for high performance air cooled motors in the summer..