I think the OP was just wondering why there seems to be some disproportionation between the quickness of the xj and the apparent power to weight ratios. And that can pretty much be explained with the gearing and drivetrain loss that's already been mentioned.
As far as the 1.8T thing goes, I raced one from a stoplight to about 50 and it was freakin close but he pulled less than a length on me. The 1.8T looked pretty much stock but I could definately hear the turbo so maybe he had intake. And my jeep just had exhaust and a drop in K&N. And the typical ricers with civics with a fart cannon and a wing I would routinely whip the snot out of, which was always hillarious.
I think it's pretty funny how there are some huge losers on this board that seem to lead a "purplecherokee-centric" life; apparently because they have no life of their own. Some of you guys need to being so high and mighty and stop flaming a guy for askin a legit question. No, not everybody is very well versed in performance, that's what this board is for!