Just got an 03 DTS and it seems to lack bottom end, or at least what I would like. I'm coming off a 99 Park Ave. supercharged 3.8, and I expected the 4.6 northstart to at least be equal to or better, but it's not even close. Granted, the 4.6 goes better at highway speeds (and very well) and would probably beat the blown-3.8 in a drag race, BUT for every day 20-50 mph speeds the blown-3.8 seems to dominate, even at lower rpm's. I'm hoping that I just have a dud 4.6 and it's just needs a fix???? I tought maybe the final drive gearing is the culpril but, the normal little up-hills that the 3.8 used to charge up (at approx. 3000 rpms), makes the 4.6 want to downshift and when it does, it goes (at 3500rpm's or higher) OK, but still no match for the 3.8. any thoughts?