Chevy and GMC Duramax Diesel Forum banner
  • Hey Everyone! Enter your ride HERE to be a part of this months Ride of the Month Challenge!
1 - 5 of 5 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter · #1 ·
I have been using Shaeffer's synthic oil in my truck. Recently, I was given 10w-40 for my last oil change. I read in the GM manual say specifically not to use 10w-40. Why? Is it bad to use 10w-40?

Teddy
 

·
Registered
Joined
·
16,268 Posts
A 10w-40 isnt a diesel rated oil.
 

·
Registered
Joined
·
613 Posts
There is a 10/30 for heavy engine use. I work for a transport company and that's what is run in the trucks. But I don't know if there is a10/40 for heavy engine use.
 

·
Registered
Joined
·
1,743 Posts
If newer truck, needs API CJ-4 rating.

Fill-out sig so we can see what you drive.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #5 ·
Here ya go!
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top