Ok I'm a bit confused about what exactly is the recommended oil change interval for my 2010 Silverado 5.3 liter V8. I'm told by both Valvoline and the local Chevrolet dealer here that my truck needs an oil change every 3000 miles. The on board computer brings up the warning at something like 7500 miles, very much like the honda my wife drives. I actually thought about changing to the newer sythetic oil that GM now offers. I'm also wondering at what point the rest of the fluids need changed out in a 4x4 truck?