Highway RPM

danj · 02-10-2009, 05:30 PM

I have a 2001 TJ with 35'' tires and 488 gears. Engine is a 4.0 L. with a 5 speed.Will it do any harm to run at 2500 RPM (65 mph) on the highway for a few hundred mile trip? What is the ideal RPM on the highway for the 4.0 L ? Thanks,

Dan

**GOLENJEEPTJ** · 02-10-2009, 05:35 PM

Don't even worry about it! I'm running 3100rpms with 4.88s with 35"s on a 32rh trans behind a 4.6 stroker.It will accelerate from there nicely.

**GOLENJEEPTJ** · 02-10-2009, 05:36 PM

Fill out your profile and welcome to JF!

2005X · 02-10-2009, 05:39 PM

i run 3100rpms with 4:56, "35s and 4sp auto at 65mph

**Imped** · 02-10-2009, 05:41 PM

35's are heavy tires. Your engine needs to be at a higher RPM in order to move them without overworking itself. The 4.0 can stay at those RPMs and higher all day long....that's where it likes to be ran.

Jeep25 · 02-10-2009, 05:42 PM

So I guess running 2500RPM is ok for a stock TJ 4.0L with 30.5x9x15?

**GOLENJEEPTJ** · 02-10-2009, 05:43 PM

Oh yea! Gas has got to be better too?

KKiowaTJ · 02-10-2009, 07:54 PM

I have put many, many miles on my heep with its current set-up. At 65-70mph i run around 3 to 3200rpm's, 35's, 32RH, 4.10 gears. I drive mine to every trail, Last trip was 2500 miles round trip. All but a couple hundred was all interstate. As stated above, With the bigger heavier tires, you want to push higher RPM's to maintain speed with wind, Hills etc. Good luck

**Kenbo-Slice** · 02-10-2009, 08:00 PM

35's, 4.56's, ax-15 tranny. I run about 2,500 rpm's at 65 - 70. Not to mention, I get like 19.5 mpg's to boot. YOur motor will be fine, and you will most likely be the most bad *** ride on the highway.

danj · 02-10-2009, 08:21 PM

Thanks for all the info

This is my first jeep and just love it!!!

**tjwrangler99** · 02-10-2009, 08:28 PM

hey kenbo, how do you manage that MPG? mine with stock tires/gears gets about that, and i figured upgrading to 33's with 4.56 would tank it... im surprised running tires as heavy as those didnt kill yours...

this gives me hope! =D

**Kenbo-Slice** · 02-10-2009, 09:28 PM

Quote:

Originally Posted by tjwrangler99

hey kenbo, how do you manage that MPG? mine with stock tires/gears gets about that, and i figured upgrading to 33's with 4.56 would tank it... im surprised running tires as heavy as those didnt kill yours...

this gives me hope! =D

To be honest.... I have no idea. A couple weeks ago I got 155 miles on just a little under 1/2 a tank. The next week, I got about 145 on half a tank. 99% highway driving both weekends. Around town... I probably get like 15 - 16 mpg's

When I had 33's and 4.56's the milage wasn't as good. The KM2's are pretty light for a 35" tire as well, and thats what I'm running now.

**Imped** · 02-10-2009, 09:37 PM

Quote:

Originally Posted by Kenbo-Slice

To be honest.... I have no idea. A couple weeks ago I got 155 miles on just a little under 1/2 a tank. The next week, I got about 145 on half a tank. 99% highway driving both weekends. Around town... I probably get like 15 - 16 mpg's

When I had 33's and 4.56's the milage wasn't as good. The KM2's are pretty light for a 35" tire as well, and thats what I'm running now.

That's pretty interesting. Sure your speedometer is correct? Anyway, that may have helped my 33vs 35 argument for my next tire. Either way, it will definitely be a KM2.

**tjwrangler99** · 02-10-2009, 09:42 PM

Quote:

Originally Posted by Kenbo-Slice

To be honest.... I have no idea. A couple weeks ago I got 155 miles on just a little under 1/2 a tank. The next week, I got about 145 on half a tank. 99% highway driving both weekends. Around town... I probably get like 15 - 16 mpg's

When I had 33's and 4.56's the milage wasn't as good. The KM2's are pretty light for a 35" tire as well, and thats what I'm running now.

most of my driving is highway... so im hoping it wont be TO bad. im planning on getting 33x10.5 BFG AT KO's... im going with 10.5's because i like driving in snow. im hoping the fact that they are lighter then the 12.5's will help out alot.

**GOLENJEEPTJ** · 02-10-2009, 09:43 PM

Sorry, not buying it with those tires and gears?