What oil do you use

[1986 Buick GX1]

I've used Mobile 1 synthetic 5W-30 and AC Delco PF52 filters for 30yrs this July 10th (changed every 5k)
Valve covers came off first time this winter for Comp 980 install and at 70k miles, super clean.
I will run ZDDP with the higher spring pressure.

 

[eagleguy]

Looks very clean.

 

[DR BOOST]

so according to this thread, you can run anything you want! We should start a thread titled..."who lost a motor due to a bad choice in engine oil".....I have been told by quite a few buick engine builders not to run the thinner weight mobil 1 in anything but a stock engine. Some guys get away with the 15w50 though.

 

[Cyrus72]

The guy I bought my GN with34 k miles with no mods. He owns a race shop in OKC and swea a by BradPenn. He told me to run 10 w 30 semi synthetic. I am no mechanic and just going with what he recommended. I bought a case for 90 bucks. I don’t know about you but it’s a lil pricey. But hey it is what it is. But if there is an oil other people swear or recommend I would be willing to try. Just explain why or the benefits over the other. Also I keep hearing about the ZDDP additive. What is it and what are the benefits? Does it carry the zinc that conventional oils do not carry? That the racing oils have ? Mind you I only put about 1 k a year. So please any input would be appreciated

 

[SCOOBY DOO]

15w40 Rotella and Wix filters. Engine is out for a fresh set of rings. After 500 1/8th mile passes at 7 flat at 100 mph the bearings are mint.