Correct oil for 307 v8 ?

[ZUBZ]

Hi all,

What would be the correct viscosity of oil I need to use on a 70 c10, 307 v8.

Has like 100k miles plus.....

I have been told 20W50 is correct.

[msgdsrf]

Depends on use. I would never use 20W-50 because of the amount of additive needed for such a broad range which break down quicker (less protection and sludge buildup). Also consider what your oil preassure is, 50 weight is pretty high for for SBC (unless your preassure is low).

Winter temps cold in J Burg that you want a Winter (W) oil? 10W-30 is commonly used, 30 is what was used, can you get 20W-40?

[Stocker]

I once switched from 10W-30 to 20W-50 in a tired 350 sbc. No problems and it used less oil between changes. But unless your engine is pretty well worn out, 10W-30 will work just fine and should be readily available.

[ZUBZ]

Originally Posted by msgdsrf

Depends on use. I would never use 20W-50 because of the amount of additive needed for such a broad range which break down quicker (less protection and sludge buildup). Also consider what your oil preassure is, 50 weight is pretty high for for SBC (unless your preassure is low).

Winter temps cold in J Burg that you want a Winter (W) oil? 10W-30 is commonly used, 30 is what was used, can you get 20W-40?

Thanks, yeah the winters to tend to get cold. I will check on 20W-40 but I am sure it is available

[ZUBZ]

Originally Posted by Stocker

I once switched from 10W-30 to 20W-50 in a tired 350 sbc. No problems and it used less oil between changes. But unless your engine is pretty well worn out, 10W-30 will work just fine and should be readily available.

Thanks Stocker, let me see what is available first locally and then decide.