Trackvw

Hi , I wanted to change my oil and maybe my Trans fluid ,

Whats the best oil to use , I am not sure if there is better oil than that recommended when it was new ?

Also trans fluid , would you change it all , or just some as I have heard people have had problems flushing out all the old stuff !

Thanks for your advise

mountainmanjoe

Don't overthink it. Use whatever oil meet the specifications given in your owner's manual. Brand doesn't matter they're all the same.

Depends. How many miles on your transmission?
How is the transmission shifting? Are the gears getting kind of mushy?
Take a sample of the fluid. What does it look like?

Triaged

I'm of the opinion that all synthetic oils are so good these days it isn't worth paying more for a great oil. I use Kirkland 5w30. I do think a good filter is worth having. I've looked at the tests and teardowns and concluded that Fram ultra synthetic XG10575 is the current best bang for the buck. It crosses over to PF63.

Trans, I'd drain, put in an extra magnet in the pan, a drain plug and fill with GM stuff.

Rednucleus

Probably being faithful with regular changes is much more important than the brand.

Trackvw

thanks , I do not have an owners manual but 5-30 seems good , I am not pulling heavy trailers or going up mountains !

What trans fluid , and are any additives worth adding ,

The truck has 155 K on it and decent upkeep

Thanks for your advise

Triaged

https://www.chevrolet.com/support/ve...&model=Express

mountainmanjoe

you can get them online now
https://experience.gm.com/support/ve...manuals-guides

doesn't matter. The fluid still should be changed every 50-60k. Maybe even more frequently as it gets up there in miles.

Dexron IV. Do not use additives if the trans works fine.

jjrbus

I am impressed often which oil to use brings on a flurry of recommendations sometimes leading to arguments. Modern oils are miraculous compared to way back so I use what ever is on sale. Which reminds me it is time for my oil change.

This guy makes some interesting comparison videos.