[JohnnyO]

I went to buy Rotella T synthetic to use as my winter oil. When I read the container it's only a CH rating

. The 2003 Duramax should take a CI rated oil according to the manual. I didn't but it. I have to find a place that sells Delvac 1.Edited by: JohnnyO

 

[JohnnyO]

Thanks for clarifying. I thought it ment it had to have both

.