Valvoline oil question

So I know everyone had their own opinions on oil, but I have a question. We purchased a vehicle care plan with my 2010 Silverado which covers oil changes and tire rotations. I was told the dealership I go to used Castrol GTX but found out they use Valvaline. I've read that Valvoline oil leaves a waxy residue in engines and that it's not a very good oil. I'd rather use Mobil 1 synthetic like I have been for that past 8 years, so if this is true about Valvoline, Ill just go the oil changes myself.

GM is supposed to use Castrol, dealer must be getting the Valvoline cheap. Like the GM dealer I worked at got a better deal on Lucas synthetic, so anything that was supposed to get Mobil One got that crap.

Maybe it's penzoil I'm thinking of. Either way, we are paying $15 more a month for this service so I would technically be throwing that away every month.

valvoline is a pretty good oil, and it doesnt have a residue,its pennsoil that leaves a build up, because it has penzaine in it, i ran valvoline for 6 years in my 5.3 and when i tore it down it looked clean as a whistle, so i say go for it. i now have a built 6.0 and run moble 1 cause its high performance and on spray

I run Mobile 1 in the 6.2. That's what it came with from the factory, so that's what it gets. I ran GTX 5/40 in my 4.8 and my 5.3. That's what it is supposed to get, so that's what it got.

Valvoline VR1 and alot more spray, mobile 1 :( no thanks

Valvoline is great oil. I've ran 4 years of conventional and 2 years of Syn Power and when i tore it apart at 86k it was very clean

Pensoil and quakerstate are both perifin based oils while valvoline is ash based. As long as you change your oil often and regularly, and as far as conventional oil goes, it really dosen't matter. It when you wait until 20k miles to change conventional oil that you run into problems. That and oil additives.

Valvoline VR1 here also

Mobil makes the non-synthetic Gm branded oil also.