Tires too big?

[n8fis]

I bought a 04 Liberty half way into last winter.
It's a 3.7 five speed manual. It's been the most
gutless thing I have ever bought. I once tried out
a 3.7 stick Dakota and it ran *almost* like a V8.

I *think* I may have located my problem. The
tires on it are 235/70 16". The door sticker and
the spare is 215/75 16".

My question is, could it be the tires are too big for
the gear train?

 

[J-Thompson]

I bought a 04 Liberty half way into last winter.
It's a 3.7 five speed manual. It's been the most
gutless thing I have ever bought. I once tried out
a 3.7 stick Dakota and it ran *almost* like a V8.

I *think* I may have located my problem. The
tires on it are 235/70 16". The door sticker and
the spare is 215/75 16".

My question is, could it be the tires are too big for
the gear train?

Probably not the tires
IIRC the manual KJ's came with 3.55 gears
this would be why it feels "gut less"
even still you may be looking for to much
I am running 255/70's with the stock gears ,3.73's, and an auto and can spin them easily on any dirty or wet surface
can some times get them spinning on dry ground

 

[tommudd]

optional tires on some models was 235-70-16

 

[Powerslave]

There is not much overall difference in 235/70 16 (diameter of 28.95") -vs- 215/75 16 (28.69"). When I bought mine, it had, and still has, the 215/75s...

 

[tjkj2002]

235/70's are a OEM Liberty tire size,my KJ came stock with that tire size.


How many miles? Might need new plugs,new trans gear oil,F/R diff oil change,and other routine maintenance items that never where done.It also would be highly suggested to have the fuel injection system and intake professionally cleaned before the plug change,can make a world of difference.

 

[Marlon_JB2]

There is not much overall difference in 235/70 16 (diameter of 28.95") -vs- 215/75 16 (28.69"). When I bought mine, it had, and still has, the 215/75s...

How'd you get 215/75s on an '06? Stock size for an '06 was/is 225/75R16.

The 215s were an '02 - '04 thing. (And looked like toy car tires!)

 

[Powerslave]

As I said, I bought it THAT way, and they were like NEW tires at the time, so I was not going to just change them... My door sticker also says 235/70/16...

 

[BigRich201]

those are the right tires the sticker your looking at is the minimum tire size. look in the clove compartment there should be a sticker in there with the tire size it should have stock along with the correct air pressure

 

[BigRich201]

one more thing i forgot to say. the dakota was a pickup truck which means less weight on the rear so thats why it felt faster

 

[kb0nly]

one more thing i forgot to say. the dakota was a pickup truck which means less weight on the rear so thats why it felt faster

Yep.. An SUV has more weight, more junk in the trunk baby, and it affects the feel of acceleration as well in my opinion.

The KJ is not a sports car, if you want that kind of performance buy a sports car. But in my opinion the KJ isn't bad at all, i think it has good performance for my driving style.

 

[Dave]

On my KJ if you open the drivers door there is a sticker showing the tire size and recommended pressure as when it left the factory. The other thing you can do as a start is get a "build sheet". It should show everything including rear end gear ratio and tire size...etc that was on the jeep when it left the factory. You bought it used I take it so this might help.

Dave

 

[Dave]

^^^oh, and one other thought. There must be (I know there is) people on here with the 3.7L and a 5 speed standard ****** and hopefully they will see this thread and chime in with their MPG and tire size.

And I know that when I had a 5 speed I always had a tendancy to wind up the motor more than necessary sometimes and that would adversly affect gas mileage. Heck, I still do that sometimes with the A/T.

Dave

 

[04Liberty]

Dude, it's a Jeep. The only factory 'fast' Jeep (and you don't wanna take this one offroad) is an SRT8 grand Cherokee, although I imagine the the GC's with the 5.7 aren't too shabby either.

 

[J-Thompson]

thinking about this more
there may be a problem with the Jeep it self
I know that ours with over sized tires is no snail
in fact I can give almost any TJ ,and any stock wrangler for that matter, a good head start and spank the crap out of them on the road
Ford Explorer V6 is also no match and even V8 gets beat by our KJ
either the Jeep has a problem or the driver is asking for to much

 

[Powerslave]

1. You can always port and polish the heads, Exhaust side
2. Intake Upgrade
3. Exhaust Upgrade
4. Dry No2
5. Wet No2 (Needs one injector per port)

Mine has a lot of get-up-and-go, don't know what your deal is. With the traction control OFF on mine (autos have this, 06 and up?), when I stomp on the gas, the rear wheels spin.

You got a manual, you should have good pickup from 0-60. Mine starts to fall off, torque wise, at about 90MPH. With a manual, if you know how to shift, you should beat an Automatic.

 

[ms5490renegade]

1. You can always port and polish the heads, Exhaust side
2. Intake Upgrade
3. Exhaust Upgrade
4. Dry No2
5. Wet No2 (Needs one injector per port)

Mine has a lot of get-up-and-go, don't know what your deal is. With the traction control OFF on mine (autos have this, 06 and up?), when I stomp on the gas, the rear wheels spin.

You got a manual, you should have good pickup from 0-60. Mine starts to fall off, torque wise, at about 90MPH. With a manual, if you know how to shift, you should beat an Automatic.

i have a 5 speed. i"ve tested the acceleration against auto libertys and found the 5 speed to be faster. also if you shift right you can take alot of suvs at the stop light. if your going 90 in a jeep, you going too fast. im not so sure about nitrous upgrade. i thought the 3.7 was kind of fragile. get an intake and a free flowing exhaust, replace your fluids, and enjoy your jeep

 

[Powerslave]

I have had my Jeep to 105... How is 90 too fast? If it is, then they shouldn't be allowed to go over 75, as that is the top speed limit in the USA for some states.

Never did understand that... They make cars to go FAST, and you can't do it, legally. It's all a programmed method to money making on all sides. Car companies make them so the law can make money off the excess speed. There is NO reason, for all intents and purposes, for a vehicle to be able to exceed 75-80MPH in the USA, ever...

 

[kjweston]

I'm running 265/75r16 with 3.73's cause I'm sixteen and don't have $3000 for 4.10's and lockers. And It has plenty of get up and go. Burn a half tank of gas doing so but that's my own fault for not reading forums before buying 32" tires. With stock 235 tires I beat my buddy's audi A6 by a car length.

 

[kjweston]

They make cars to go FAST, and you can't do it, legally. It's all a programmed method to money making on all sides. Car companies make them so the law can make money off the excess speed. There is NO reason, for all intents and purposes, for a vehicle to be able to exceed 75-80MPH in the USA, ever...

good point. never really thought about that.

 

[Jeepin05]

For 90 being too fast, first off it's an SUV. Second of all, the stock tires probably aren't rated much higher than that. Think of what would happen if one blew pushing 100...

IMO it's just common sense to not push it with an SUV.

I agree that the 3.7 seems to be peppy enough with an auto, and should be even faster with a stick.