I filled up at several different stations (not exclusively Chevron) twice at Valero stations once at an HEB and the rest at Chevron. I really don't feel like it is Chevron gasoline per se rather that the engine in my truck is not high enough compression to really need a slower burning gasoline. The results I got seem to bear that out. I have a Pro-Dry drop-in filter, Magnaflow
muffler, 265/70/R17 tires and 5100's all around with the fronts set on 1 notch up so the lift is not excessive. In other words, the truck is not radically altered from stock. So my results did not indicate (to me) that it is a benefit to use 93 octane gasoline. Someone else may get better results on the higher octane from their truck which I cannot explain. All I can say is for the considerable higher cost of premium, the benefits were not there. It would be very interesting to know for sure what the control algorithms are implemented in the computer(s) for the 4.0 litre V6 engines. Also what the actual compression ratio is supposed to be in the V6. 93 octane is primarily there for use in higher-compression engines (and air-cooled etc.) to help prevent detonation due to higher compression and/or hotter running (air-cooled). Usually a higher-compression engine is said to be running well over 10 : 1 compression ratio.
BUT if someone else's truck seems to run better on 93, then pay up! I am looking forward to getting all that 93 out of my tank so my truck will accelerate again.