I have been running GC in my 98 f150 4.6 v8 for the past 5k miles and i'm getting ready to dump it. It still looks good but i'm ready to dump it and UOA. Maybe the UOA will make me say otherwise, but i'm really not hugely impressed with it. I lost gas mileage, and a hint of performance with it. And the fact that I have to hunt for it is a bit of a pain. Anyway, i'm shopping now for something else to run until early winter here. I was going to run 5w40 Truck and SUV, but now i'm thinking of 0w30 or 0w40 mobil1. I want to stick with a synthetic in the truck so i'm not running the motorcraft blend. Any opinions?