better performance between '00 and '01?

I have a 2000XJ, 4.0, aw4. My jeep runs decent, dosnt skip or anything. i get about 21.5mpg highway going 55mph. My brother has an '01 XJ, same engine configuration, and his jeep seems to have more power than mine. What differences would there be between his and mine to make his seem to run better and have more power? computer software? different injectors? I do all the work on my jeep and have a replacement K&N filter etc, so the obvious to me to check, everything seems good. Any ideas?

They should be identical. Maybe its just in your head?

Maybe he has deeper gears or smaller tires, which would make it accelerate faster.

Have you actually driven his, or are you using the passenger seat ass dyno in his? There are slight variables that can make little differences, but I agree that smaller tires would be equivalent to giving him better gearing. If the tires are equal, then it could be that his has been babied a little more than yours?

He has the same gears, same size tires. An older couple had my brothers jeep before him (or so the dealer said). i drove his and it does seem have more spunk. i realize maybe it could be in my head, i havent ruled that one out yet. haha . i have an extra 02 sensor and maybe ill throw that in to see if that makes any difference. worth a try and its free! My dad's friend works for a jeep dealer and he said i could upgrade my software to a better one and maybe thats what my brother has on his. who knows what the software has in it? better advance curves and what not? seeing my '00 was the first year for the coil pack ignition, maybe they didnt get the bugs out of it yet? maybe i can get the computer flashed and then see what happens. Right now it just seems like ya hit the gas and its just kinda doggy a little. i know its not a race car, but if i can upgrade it for different software i will....and who dosnt like upgrades? )

Flashing the computer will give you all latest updates, but seeing as how they stopped producing them the following year, they probably haven't done a lot of updates since then for that particular PCM. I can't knock it, because I'd do it too if I were you, and it was free. Just don't expect a lot. You could always throw a stage one jet chip in, and really change the parameters... I have a true CAI, header, and exhaust on my 97, and it's fast... If I can get it to start! LOL! Stage 2 Jet chip going in next year.

Weigh them. A hundred pounds difference is very noticeable. Maybe you have heavier tires, rims, or carry tools or spares?

At least get them both out on the freeway and punch 'em from 50mph side by side. Eliminate your imagination. Also compare rpms at 50mph to see if gearing and tires are identical. If one is really faster, could it be blockage of the catalytic converter????

My sister (Rightseatsis) has an 01, I have a 00. Hers feels like it has more power, but I have larger tires. That makes a difference in butt dynamics.