API SH 30 hello from new guy

[ARCOgraphite]

The 30HD may be modern semi- synthetic group II and III with near 10w30 performance

where as the 15w 40 may be group I and II.

 

[Linctex]

I've got 300,000 miles on my 454

Been using 15W-40 (cheapest found on sale anywhere) - it is all it has ever seen.

If you want to make it to 300,000 miles - run 15W-40

 

[rummy]

Rotella T5 in 15W-40 would be my choice year round.

If I were going to be parked in extremely cold weather than I would run Rotella T6 in 5W-40 flavor. If you think this is to light, than the goldylocks oil would be Rotella T5 in 10W-30 flavor. Not to thick, not to thin. Just right!

I'm sure that whatever modern HDEO you choose will be fine.

 

[racin4ds]

Agree with many above, put a quality HDEO 10W30 in it and be done! That ancient old BB Chevy isn't going to care!