Cat engines come in many power levels,some ratings are motorhome specific or because of cooling or transmission capacity. If you feel you are lacking power(525 is probably lots) Cat can put it on their chassis dyno and give you a detailed report. A reflash of your computer is $5-600 plus cost of dyno time. Your right foot and road speed has more to do with fuel economy than any engine rating. Unless you are pulling a large trailer behind,100 lbs. torque would not be felt in the drivers seat. Hope this answers your questions.