Just picked up a 4.8L gasser to run around. Got all this Delvac 1 from the max, any problems runnin the 5-40 in a gasser? I would think not because it is the same as the "truck and SUV" oil, and most "trucks and suvs" are not diesel!

In my 6L, they said 10w-30 was acceptable instead of 5w-30 due to where I live. No one has mentioned a _w-40 as an acceptable substitute. I'd check with a stealer to be sure, however.

Biggest thing to look for is the API classification, usually on back of bottle, in your case it should be SL or SM.... C is for compression ignition, S is for spark ignition. Other than that I don't like the weight span... 5 to 40 is a lot of friction modifiers added to oil, but if classification is OK use it. Only one I've heard to be a definite NO NO is 10w-40

i had a buddy use shell 15W40 in his 350 chevy for as long as i have known him. he has never had a problem

Stupid me, I read label, everything is cool!