I drive a car with a 5.7 Hemi engine - The recommended fuel is midgrade 89 octane. I have noticed the car runs better if I use premium 91 octane fuel. My question - Is there a greater risk of fuel dillution to my 5w-20 oil running 91 vs 89 octane gas. I usually use Castrol Syntec 5w-20.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rookietech</div><div class="ubbcode-body">Does motorcraft oil have cleaning agents like valv. and pennzoil? </div></div>I believe all synthetic oils have some type of add pack nowdays.