rush1517

How is towing capacity measured? What can you do to increase it?

The reason I ask is: The JK with a full box frame and a 3.8L engine is rated at 3500 useless lbs. However the little girl Liberty with a 3.7L engine is rated at a respectible 5000lbs. WTF? How is this possible?

Please help so I don't have to get rid of my JK for a total chick ride Liberty just so that I can tow my boat.

pearl-drum-man

There are numerous factors such as suspension, engine power, and cooling that factor in. The JK is definitely designed for off-road use, not so much for towing. WHile there may be mods you can make to improve the towing capacity, from a liability standpoint I think the manufacturer rating will always stand.

EDIT- BTW, I have an 07 JK and my fiance has an 06 Liberty, the "girly" Liberty will annihilate the JK off the line and on the highway, even though it's only rated for 5 more HP.

rush1517

OK, but why the 1500 lb towing difference? Any Ideas?

Abd BTW - I'm not a "liability" kind of person. I've seen a few of the answers on here about towing capacity... I think there are a few lawyers that work for the govt on here answering questions. Some of these guys need to ease up a little... or live a little.

Keith615

I am willing to bet it is transmission cooling capacity that is the biggest contributer and maybe vehicle weight.

Both of those are just WAGs though.

Lorrel

I think in addition to what has already been posted, vehicle wheelbase and length, as well as GVW is also factored in. I cannot explain the large difference. She must have a 07 or before Lib, as the 08 Lib has a rated TC of 3500, same as the Wrangler Unlimited. The newer standard Wrangler's are rated at 2000. They however only have a GVW of 4900, with a wheelbase of 94.5" and overall length of 162.9" The 06 Lib 6spd has a TC of 3500, as listed under the specification section of Jeep Horizons.
I can say I rented a trailer one time, and the guy asked my vehicle make. When I told him a Jeep Cherokee, he said the size I wanted could not be used by that vehicle. I told hom I had HD springs with a 6" lift. He told me I could come over and they would check it out. After I got there and they lookd at the XJ, he said there would be no problem, so maybe the suspension is a pretty big factor.

pearl-drum-man

I don't have any concrete verifiable answers, only Jeep engineers could offer that so the best we can do is offer speculation. IMO, the Liberty suspension is better able to handle the extra load (it certainly isn't as supple as that of my JK) and as I mentioned, the Liberty definitely feels quite a bit stronger at take off and on the highway at speed. The Liberty also has a lower center of gravity, FWIW. I suspect the Liberty may have better cooling design then the JK as well (just a guess though).

As for liability, it may seem inconsequential and cerainly there have been plenty of examples of people exceeding the tow ratings with no issues, but I have seen multiple examples over the years where people have been held legally responsible for things like this in accidents.

pearl-drum-man

I would suspect if anything 6" of lift would reduce the towing capacity. Weird.

only_in_my_jeep

Given the specs online the tow rating is the same. Not sure if the specs are the same for the older Liberty. This is because given the vehicles weight (about the same) and length (about the same) they can tow the same weight. Now this is an unlimited and a Liberty the towing for the 2 door is less due to the smaller size and weight. If you look at the Cherokee and commander you will see the vehicle weight goes up and so does the tow ability. It's not that the Wrangler's engine, transmission, and suspension will not handle it but rather the heaver the load the heavier the tow vehicle needs to be in order to keep it under control especially in a stop. This is the big reason I kept the old suburban just in case I need to hook to something heavy and tow it.

only_in_my_jeep

The HD springs do affect the load bearing capeabilities of the vehicle. In other words instead of a max of 500# tounge weight you could go 1000# and still not have any flex or bottom out (figures are not correct but you get the idea). The towing capacity however does not change as it is a dirrect function of vehicle size/weight to tow weight. The lift however influnces the geometry and can reduce the ability to tow something safely.

Lorrel

I agree. I believe when the guy at the rental place saw the XJ, he just figgured it was a beast and could handle the trailer.

BTW, while I was there we got to talking and he mentioned that they will not rent a trailer to anyone driving a Wrangler with a soft top. Something about liability.
Hmmmmm??