: Oil Viscosity 1981 Eldorado 6.0

11-25-12, 03:01 PM
I'm using synthetic royal purple oil in all my vehicles. Based on the temperature chart in the manual and the temperatures I experience in California, it says to use 10w-40. I have two other newer cars that use 5w-30 and that's what is available right now. Will I get any benefit out of purchasing new, thicker oil? Or just use the 5w-30? The oil in there right now is clean and can wait another week for more to come in the mail, should I go ahead and put 5w-30 in there or wait and order another viscosity?

11-25-12, 04:01 PM
Most new vehicles want the 5w-30 oil. But the 6.0 in your 81 is a bit different. It doesn't have a roller cam like newer cars do for one thing. However, I don't think the 5w will hurt, but 10w is what the manual says and that's what I'd go with.
Just me tho..

11-25-12, 10:55 PM
10w30 or 10w40 will do just fine.