Speed and mpg potential of 2.5 TJ?

[ron521]

I'm looking at a '97 TJ with 2.5 engine and 5 speed. Vehicle is almost stock, with slightly bigger B.F. Goodrich tires (I'm guessing 30's) on chrome rims.
I've heard some comments about lack of power in this engine, however surely it isn't so weak as the old Super Hurricane flathead 6 which pushed my old Willys?
I'm kind of attracted to the idea of a Jeep which might give 20 mpg or better, so my question is: Just how fast can I expect such a vehicle to go on the highway? 60? 70? 80? And what fuel mileage might one expect at a constant speed?
I expect that I'll end up installing an electric fan, cat-back exhaust, and an air-filter conversion, but would like an idea of what sort of baseline I might expect.

[Bounty__Hunter]

20mpg is on the high end, best I've seen is around 21mpg and now average 15-18mpg with 36" tires and 5.38 axle gears. Your speeds are sustainable, but don't expect to pass other vehicles, and plan on down-shifting for the slightest grades. With my gearing and engine mods I can now hold 5th gear and often accelerate up highway grades that required me to downshift in the past.

The 2.5L is a good engine and a lot of fun after a few power mods. Just know what you're getting into and all will be well.

Check out www.4bangerjp.com for a good 4cyl jeep forum.

[mikedrees]

i have a 97 2.5 5-speed & i get a pretty constant 20 with 235/75-15 goodyear wranglers, k&n filter with a gutted stock airbox, 4.0 throttle body & a cheapie ebay spacer. the sweet spot for mileage seems to be 45-55mph. top speed is no problem & i cruise with the i-10 traffic at 85 pretty easy. i am in the procees if doing the e-fan & adding a firepower ignition system to see if that adds any.