My 1982 Camaro has a 350 smallblock, i am having trouble with figuring what oil to use. It use to run 20w-50 which is way to thick, and 10w-40 is being burned up in a few weeks. I have 5w-30 in it i put in today to see what it would do. Can anyone help with this?

 

you do of course realize that if it's consuming oil like you say that it's not because of the viscosity? You have a larger problem which is going to require tearing down the engine

 

what temp weather do you usually drive in?if ur burning oil its not because of viscoity,maybe valve seals,pistion rings,but its prolly the old chevy oil leak. if ur in cold weather you use somthing like 5w15 or stright 15 weight if your in hot weather you can use 10w30 or 15w30.1st number is how thick it is when hot second is how thick it is when its cold

 

not exactly

a multi-viscosity oil has additives to allow it to protect like a higher weight oil when the engine is hot, around 210 degrees F. In other words, a 5w30 oil is sae 5 oil which is free flowing and good for when engines are cold (startup) but then protects like a 30 oil when the engine is hot.

But, here's the rub. If you wait too long between oil changes (go by hours, not miles) then "thermal breakdown" like you see on the Castrol commercials occurs. The oil will slowly lose its high temp protection and become a 5w20, and then 5w 15 and ultimately, if you wait long enough, a 5 weight oil which is no good for high temps and rpms.

So, to the OP, you need engine work. To affliction, I hope this cleared up your misconception

why do I use "hours not miles"? I'll take 5k highway miles between oil changes any day of the week over 2500 stop and go city miles or just idling. The city vehicle engine is probably running 30%-60% more time.

 

Thanks for the replies, it is running now in the hot alabama weather. So are you sayin that im gonna have to have engine work done? cuz thats not rlly what i was hopin for...But its runnin the 5w-30 as of yesterday.
I was hoping it would be i needed to run a different oil

 

nope, not saying that you can't run it. I am simply replying to your query about oil consumption. You can try a bottle of bardhal or Lucas which cost anywhere from $9-$20 and see if it lessens the oil consumption.

Just make sure you keep a quart or 2 of oil with you and check often. You can run for years with an oil burning engine.