I was riding with a friend in his 03 6. 0 psd and it seemed spool up was slow but once it did it took off. I was wondering could it be Gears tires? or is there a big diff in power ratings for the newer trucks as aposed to older? I am looking to bomb (hopefully soon) but was wondering if something else I overlooked? seems my truck had a lot more power when I got it @101k and it has 130k now power service every 2 tanks. any help would be great.