Top Speed of 2.5 Manual TJ?

S

stantron5k

New Member
Original poster
Joined
Mar 23, 2024
Messages
9
Location
Florida
Greetings everyone!

I bought my first TJ ('98) a few months ago and I can't get it over ~60 mph on a straight flat road. It's a 2.5L/4 cylinder, manual transmission, no lift, and Falken Rubitrek R/T tires. I had a YJ 4 cylinder years ago and I don't recall it struggling to hit 65 mph.

Does this sound typical for a TJ?

My TJ's CEL isn't on and I replaced the front O2 sensor. The previous owner did have an aftermarket AC added to it, which I haven't used. I'm not seeing anything that I can attribute the sluggishness to. I know it's no speed demon, but I'm concerned about being able to drive it on the highway only maxing out around 60 mph.
 
Our stock 2.5s cannot handle large tires without some consequences. They came from the factory with 27" or 28" tires on 15" wheels, I believe. Something else to keep in mind is the weight of the tires, which can vary significantly even in the same size-range. And also the weight of the wheels themselves. This is why many owners of the 2.5 end up re-gearing as they modify their TJs.

But if you're right about the tire size, it doesn't sound too bad. What you're describing is something I would expect for someone running something more like 32" tires or higher.
 
Tires and gears as well as both unsprung and sprung weight play a large part. At 5k elevation, pretty heavy rn with armor,winch, hardtop,full doors, also have 33in tires but am geared at 4.56 as well. I can cruise 70-75 as long as we’re not having 60mph wind. If you’re geared with the stock 4.10 and are shifting at just over 3k (some people arnt getting the rpm high enough, like shifting at 2.5k and then saying the motor is bad, no that’s just the 2.5l and it’s peak is at 3.5k rpm so get the rpm’s up close to that and make sure it’s not just driving style before ruling stuff out) , you should be able to hold 65 (that is how I was with stock gearing and all things the same) where ya live can help too bc idaho being higher up with 70mph speed limits and steeper sections definitely make me feel slower but when I was back east with sea level, little hills, and 55mph speed limits I never felt slow.
 
Regearing is a solution. I run the 4 banger 5 speed and can easily hit 80 in 5th but back off because...it's a Jeep. Mine's regeared to 5.13 also, but I'm running on 17X33's (should've stayed 15") fwiw.
 
Top Bottom