Api Sl, SJ

[Paul K.]

I found 2 cases tropartic 10W-40 oil at the auto parts store that was way on the bottom shelf with the SL, SJ API, Rev. 10/2002, I have been using Delo 400 15/40 for the last 2 years, Is oil okay and does it do any harm to switch, The first 4 years of my 66 327/350 were with SL 10W-40 Valvoline
thanks

Paul Klemetson

[Duke W.]

Re: Api Sl, SJ

SL has a P limitation of 0.10 percent, which is less than CJ-4.

Also, oil has a shelf life. I've seen old bottles of oil - probably at least five years old, that had a black sludge at the bottom due to additive drop-out.

One of the Web references in my oil article in the last Corvette Restorer discusses oil shelf life if you want to take a deeper dive.

It's practically a no-brainer to go to any auto parts store and buy fresh CJ-4, but it's your car...

Duke