Hello well first off i have an 06' seirra 2500hd 6.0 litre! Its fairly bad on gas and i cant decide whether or not i should do any performance or body upgrades? It has 130,000km's which is decent for a used gas is it not? But how much life would u say i could get out of it? Its horrible on gas is the other thing and im not sure whether to keep it for a few years then sell it and buy a newer one im having a delema help please!!