JK Wrangler - Rental

[lupinsea]

Also while on vacation, we rented a JK Wrangler for the day in the town or Ouray, CO. There are a TON of high-elevation 4x4 routes in the San Juan mountains (the cluster of mountains containing Ouray, Telluride, Durango, Silverton, and the headwaters of the Rio Grande, etc.) and we wanted to do some exploring.

Rental rates are pricey at $150+ / day but at least the rental companies (small time mom and pop type outfits) encourage you to take the Jeeps offroad, albeit with severe penalties for damages. And $150 could have been a river rafting trip that would have lasted maybe 2 hr instead of an all-day Jeep adventure so the price isn't too horrible when looked at that way.

Anyways, this was the fist chance I had to really drive one of the JK Wranglers a lot and it was a bit of a mixed bag for me. I've riden in YJs, I've riden in my friend's 4-door JK with an AEV 3.5" lift, and I've owned a TJ for the last 8 years.

Engine
Our Jeep for the day was a 2-door JK with the "old" 3.8L V8 that first came in the JKs (not the new Pentastars) and the 6 spd manual transmission. Most of the interior carpeting was stripped out (easier maintenance for the rental company). When I first read reports at how gutless the JK's new (for '07) 3.8L V6s were I thought it was silly. On paper they're putting out more power and torque than the old 4.0L. But I was wrong. They are gutless. The engines might make the power but not down low where it's needed in the Jeep. In 2Hi or 4Hi there is just nothing there which is where you want it for any driving on pavement. I could swear that my friend's 2.4L 4 cyl. TJ had more get up and go. Add into this that the JKs gained about 800 lb. over the TJ and it's no wonder the Jeeps feel under powered. On the trail, however, in 4Lo there is plenty of grunt but it's because the low-range gearing in the transfer case comes to the rescue. For most of the day on the trails we were in 2nd gear, 4Lo so this lack of power was a non-issue.

Transmission
The transmission, or I should say, the shifter, was just awful. Maybe I've gotten spoiled on the Miata (the ZHP shifter even felt sloppy and vague to me), but the JK's manual shifter was all over the place with huge, looooooooooooooong throws between gears. When shifting there was so much slop that you're more or less guessing which gear you're shifting to. And when not shifting the shift lever is bouncing and wiggling all over the place like it's on a caffeine withdrawal that it's almost distracting. Yet for all the sloppiness I rarely had any missed shifts and managed to get the rig into the right gear.

The big problem with the manual option was the horrid clutch. I swear there must have been a good 6-7" of travel before the clutch started to grab. It made everything very unpredictable when getting going from a stop on a steep grade (and there were lots of steep grades). I never even bothered to see if you could heel-toe shift in this thing. But mostly that is because such ability is pointless in a Jeep.

Ride
The ride on the 2-door JK was smoother than my TJ but I'm not surprised by that with the JK riding on stock suspension. Yet it felt more "jiggly" than my 11 year old Jeep. It also felt like it wallowed a little more. Sort of like you were driving on top of a waterbed. And while driving it the JK felt bloated compared to my TJ which felt like it tucks in more. Part of this is the fact that the JKs are 5" wider but it makes a surprising difference. I think part of this is that the hood is now so broad and wide. Otherwise, the solid axles felt reasonably well controlled under the Jeep, much more so than on my rig when hitting bumps.

In short, my friend's 4-door JK on the 3.5" AEV lift and 35" tires has had the best on-road / dirt road Wrangler ride I've experienced. My TJ has been the second best. It's firmer than the rental JK we had but it feels more pulled-together and buttoned down. Then the rental 2-door JK. Then the harsh leaf-sprung Jeeps.

Soft Top
I had the chance to put the soft top down (and back up at the end of the day) and I must say that I like it. Operationally it's a big improvement over the TJ (which itself was a big improvement over the YJ). Instead of having plastic rails that needed to be tucked or untucked from the door surrounds on the TJ (which required a pair of pliers) the JK's top had these clips that snapped into some spring loaded receptacles. Just press a button and that part of the soft top was released. Plus, the JK's soft top allows you to fold back just the part over the front seats without folding down the whole top. And the back sail panels were rigid on the JK. So, operationally, the soft top is great. But looking at the soft topped JKs around Seattle they look like they are showing more wear sooner than the TJ tops. So better functionality but a step back on durability?

Fuel Economy
The JK did seem to do pretty good on the fuel economy. I was really surprised that we turned in about 12.X mpg at the end of the day and that is with spending MOST of the day on the trails driving up some incredibly steep trails and passes. Typically, my Jeep gets about 4.5 mpg on the trails and probably would have turned in about 6-7 mpg milage for the same amount of driving we did that day.

Conclusions
We had a lot of fun exploring Colorado's mountain tops and I really had a good time out in the JK and had fun driving it. However, I'm not sure I really liked the JK all that much and I'm not sure it's better than the TJs. If you go down a check list of technical improvements the JK made over the TJ it's mighty impressive with stronger, stiffer frames, stronger axles, yadda yadda yadda. Yet the "feel" of the Jeep is different and it's not one I'm terribly fond of.

Frankly, I'd rather keep my 11 year old, beat up 90k mile TJ than drive a JK. Maybe someday I'll change my mind but for now I'm in no hurry to "upgrade" and would advise any one else (FC?) to save their pennies and look at picking up a TJ if you want a Jeep. The only big selling point I see the JKs have over the TJ is the 4-door model. Oh, and now the Pentastar V6.

[JST]

Originally Posted by lupinsea

Frankly, I'd rather keep my 11 year old, beat up 90k mile TJ than drive a JK. Maybe someday I'll change my mind but for now I'm in no hurry to "upgrade" and would advise any one else (FC?) to save their pennies and look at picking up a TJ if you want a Jeep. The only big selling point I see the JKs have over the TJ is the 4-door model. Oh, and now the Pentastar V6.

It's been a long time since I've driven any Wrangler, but my brief experience with the Pentastar in a rental Charger leaves me wondering whether it's really the right engine for that application. It's got good power, but like all of the 3.X liter, 300ish hp V6s out there these days it really only makes that power higher up in the rev range. In the Charger (which is, admittedly, a big, heavy car) it felt kind of gutless unless you really caned it.

[kognito]

When we were there, we did the Silverton-Durango steam train ride

If I had known you were going out there, I would have recommended it!

[FC]

If I get one, it would have to be 2012+. Given the insane resale values, I could even go new. But it's likely we'll just get a used GL.

[lupinsea]

Here's the dyno comparison between the old 3.8L V6 (black) that we undoubtedly had in our rental Jeep and the new Pentastar 3.6L V6 (green) in the JK application.






For comparison, here is what the old Jeep 4.0L I6 engine torque looked like (this is the engine I have in my TJ).



Most trail driving happens around 1500 rpm +/- and in many cases between idle and 1500 rpm. As you can see, both of the V6s have less torque down low than the old 4.0L. But the new Pentastar has a decently flat torque curve above 2000 rpm. Not that that rpm range is much useful on the trail but it's handy for the road which is where I think the major weakness of any Jeep is.

[GregE_325]

I can only imagine how bad the old ones must be. My 2012 Wrangler with the Pentastar is an absolute slug to drive. No amount of feathering the clutch and gas can get the thing off the line in any decent time, which becomes problematic where there are several turns on my commute that require a bit of hustle.

On the flip side, my experiments in hyper-miling are going well. Keeping the cruise set at or below 65, although painful, has raised the average MPG from 19 to 23.

[lupinsea]

Better than the ~14 mpg I see in my TJ.

Also . . . manual? Must not be a trail Jeep?

[GregE_325]

Originally Posted by lupinsea

Better than the ~14 mpg I see in my TJ.

Also . . . manual? Must not be a trail Jeep?

hahaha!!! Well, you got me. It does spend most of its time on the paved roads. But I will admit that it does spend some time off-road. My house in on 5 acres with 200 acres of wooded trails surrounding it. I do ride through those trails on occasion.

I also sometimes go out driving with my wife's cousin, whose family owns quite a bit of land nearby. He has an older Jeep with a lift kit, and I've been out with him in my shiny new one. He's taken me in all sorts of trails, rivers, mud bogs, and rocky hills. Other than a few very large rocks that require the clearance he has in his Jeep, my Wrangler was able to handle everything thrown at it. I do understand your point about the transmission. I can smell the clutch melting on some of those trips. An automatic would be a more practical choice, but I've always preferred shifting my own gears since I started driving.

It really is amazing how capable a stock Jeep is. I've been very surprised and the things that I've been able to driver over/through/around. I don't have lots of off-road experience, but the Jeep makes it easier than it probably should be.

-- Greg