2015 Silverado 3500 (6.6L)

WayneTrencher · June 27, 2020

Just bought a used Silverado 6.6 L , don't know what fluids are in it and I really am not going to take it to a dealer so that they can hassle me to sell me this and that service and scare tactics about how I need something when I just want to change the fluids. (At least the dealer in my area is a hassle, long wait times too!).

I did some searching for an hour and was looking for some top fluids other than what the dealer or lube express/valvoline puts in and found the following.

https://www.searchforparts.com/oil-change/chevrolet-trucks-2015-silverado-3500-pickup-6.6l-8 (I like this page since tranny and filter parts are all on one page)

also like this, seems solid!

https://royalpurpledirect.com/duralec-super-15w-40/

or maybe you have a suggestion for someone who has a heavy foot and revs the engine up hard like me. Just look at my avatar! LOL

ChevyorDie · June 28, 2020

I know. I can't stand the dealer. I used Royal Purple and Mobil 1 for years. It got to be too expensive doing oil changes after a while. I use my truck for work and somebody my boss has me driving nearly 1,000 miles per week. I don't have a diesel, so I now go 15,000 miles on an oil change using that Amsoil stuff. For diesel, I think you can go around 2 or 3x the drain interval or something like that. A friend of mine had an F-250 and used that stuff. I think that's what he told me. I can't remember since it's been so long. He does a bunch of work on some kind of vehicle prep for used cars all over South Florida. He drives from Homestead to West Palm every day. I hate to see his diesel bill. That's insane. Anyway, coming from an RP user, I'd give that Amsoil stuff a try. It ends up being cheaper since you can go farther. Read the bottle when you get it. Maybe it will tell you how far you can go (I think. I may be wrong.)