BTW watch when you are buying Mobil 1. Last time I went to Crappy Tire they had many kinds of Mobil 1 on the shelf and none said Dexos. I had to ask for it and it was hidden in the back behind the parts counter. Today I looked on CTC website for Mobil 1 and guess what they have 7 different types. I won't list them all here, but I only saw two that said Dexos. They were Advanced Fuel Economy and just Synthetic. Now here it is even more puzzling because you could buy both these types either with or without Dexos. They also have Mobil Delvac 1 to add more confusion.
Here is the definition of Dexos - Dexos is a motor oil specification developed by General Motors (GM) for use in their vehicles. It is a performance-based standard that specifies the quality and performance requirements for engine oils used in GM vehicles.
Now here is what Delvac is - the product was developed in 1925 as Diesel Engine Lubricant by Vacuum Oil, or DELVAC.
Looks like Mobil 1 oil is like saying my car is GM. If you have a C7 just watch out.....and a C8 good luck.....LOL