ilPistone.com: Jeep Wrangler

It?s Here! (Well, Almost?)?2007 Jeep® Wrangler

In the automotive world, there?s something a bit unusual that?s unique to long-lived vehicles.

?New? models seem to last a long, long time.

Take the civvy Jeeps, for example. When you?re talking about a 60-year, continuous production history, the ?new? classification becomes somewhat relative. The current TJ hit the scene in 1996 as a 1997 model. For enthusiasts who?ve held a driver?s license since at least the mid-1980s, the TJ is still thought of as the ?new? Jeep. Can?t be helped.

Well, this year the TJ can finally move from freshman to sophomore status, because its replacement is on the way. Code named ?TK,? the 2007 Wrangler has been completely redesigned?inside out, front to back, top to bottom?yet it hasn?t exactly strayed off the reservation.

In a nutshell, the ?07 Wrangler is designed to accomplish two primary objectives: improve on- and off-highway ride and handling (characteristics which are usually at odds with each other, but it sounds as if the DC engineers may have gotten the job done), and significantly enhance interior space and passenger comfort. Were these goals met? On paper it sure seems as if that is the case. We?ll have to wait until a comprehensive road and trail evaluation is completed later in the year to make the final assessment.
Foundations

As expected, the Wrangler continues the traditional ladder-frame/steel body configuration. Torsional stiffness of the frame has increased 100 percent, and there?s a 50 percent stiffness increase in the body. Both on- and off-highway, this increased stiffness is a plus. Reduced flex here allows the suspension components to better do their job. On-road, that means road irregularities are more localized to the suspension system rather than being absorbed by the frame and transferred to the body. In short, it?s a big step toward smoothing out the ride.

Additionally, the frame has been configured to provide an extra two inches of wheelbase and a 3.5-inch wider track width, bringing the wheelbase to 95.4 inches and the track width to 61.9 inches. The benefits here will certainly be felt on the highway, particularly in the corners. On-center steering should be one benefit, as well as reduced yaw and pitch for flatter cornering at speed, and a slight reduction in brake dive.

As for the suspension system, there are no big surprises. Front and rear live axles continue, of course, as do leading arms (front), trailing arms (rear), and front and rear track bars, coil springs and stabilizer bars all around. This is all familiar turf, which should make for quick aftermarket integration.

The TK will come in three trim levels?X, Sahara and Rubicon. Standard on the X are 16x7-inch wheels and P255/75R16 Goodyear Wrangler STs. The Sahara comes with 17x7.5-inch wheels and P245/75R17 Wrangler SRAs as standard. For the Rubicon, standard fare is also 17x7.5-inch rims wrapped in LT255/75R17 BFGoodrich Mud Terrains. Interestingly, the Sahara can be optioned with large 18x7.5-inch wheels sporting P255/70R18 Bridgestone Dueler 693s.

While these wheel/tire packages are noteworthy for obvious reasons, they also differentiate the shock packages. Since the X model will be the trim that the none- or occasional-off-road buyers will likely purchase, low-pressure gas-charged shocks come standard. They?re supposed to provide a finely tuned balance between jounce and rebound for better on-road suspension response and a more predictable ride. The 17- and 18-inch wheels available on the X and Sahara, however, come with robust high-pressure monotube shocks with Low Speed Tunable valving for better off-road performance. Across the board, the TK?s lower spring rates should also contribute to a more pleasing on-road experience.

As for steering, the Wrangler still doesn?t get rack-and-pinion, but the recirculating-ball system is engineered with a stiff cross-car steering linkage for precision feel.

Here?s a new one?an optional electronic-disconnecting front stabilizer bar. Jeep calls it the Active Sway Bar System, and it?s designed to deliver a 28-percent increase in suspension articulation. With the front bar connected, the new Wrangler?s Ramp Travel Index (RTI) is 652. Electronically disconnecting the sway bar bumps the RTI to 832. We?ll have to wait and see how well this works, but here?s another example of Jeep cutting into the aftermarket action.

Now, for the performance data all you rock-hoppers are wondering about. When equipped with the 17x7.5-inch wheel/tire package, the Wrangler delivers as follows: 44.3 degrees approach angle, 25.4 degrees breakover angle and 40.4 degrees departure angle. Front and rear axle-to-ground distance is 10.5 and 10.2 inches, respectively. You can check out all of these specs in detail by scrolling to the bottom of the specifications page.

Back for another round are the Dana 30 front and Dana 35 rear axles as standard equipment for the X and Sahara models. The Rubicon, of course, still gets Dana 44s front and rear, along with electronic-activated front and rear lockers.

One final note in the suspension/handling category: All Wranglers will come standard with the Electronic Stability Program (ESP). ESP taps into the ABS system to maintain directional stability. Three different settings allow the driver to customize the ESP response depending on the road and driving conditions. And speaking of brakes, four-wheel discs replace the former front disc/rear drum setup. For off-roading, the ABS enables sustained wheel lock-up.

owertrain

Well, we knew it was coming, but the heads-up still is not enough to shake those melancholy feelings of losing the in-line six-cylinder powermill. Nevertheless, the deed will be done once the last 2006 models leave the factory. In its place, and in place of the 2.4L I4, is a 3.8L V6.

Like the old Power-Tech I6, the V6 continues the overhead valve tradition, but now the heads are constructed of a lightweight aluminum alloy rather than cast iron. And although displacement is down 11.5 cubic inches, horsepower is up by 15 and torque gets a miserly 5 lbs-ft bump (albeit at 4,000 rpm compared to the 3,200 rpm rating of the I6). Since DC hasn?t published horsepower and torque curves, we don?t know how well this engine?s output will translate to rockclimbing, mudslinging power, but highway towing capabilities should certainly get a lift. As for fuel economy, that?s anyone?s guess at this point.

Back for an encore performance is the standard NSG 370 manual six-speed and the 42RLE four-speed auto. No major changes here except the six-speed?s standard axle ratio is dropped to a more highway-friendly 3.21:1 versus the old 3.73:1. A 4.10:1 gearset is optional and comes standard with the Rubicon. In regard to the automatic, the axle ratio is raised from 3.73:1 to 4.10:1.

Moving to the all-important transfer case, say goodbye to the NV231...sort of. In its place, and featured on the X and Sahara models, is the second-generation Command-Trac NV241. Like the NV231, this is a part-time, two-speed case with the same 2.72:1 low-range gearing, and it?s backed by a Trac-Lock limited-slip rear diff. Carrying forward on the Rubicon is the NV241OR Rock-Trac case. Again, it?s a part-time, heavy-duty, two-speed unit with a 4.0:1 low-range. As mentioned earlier, the front and rear diffs are of the electronic locking flavor.

Before we leave the powertrain discussion, we should point out the Electronic Roll Mitigation (ERM) system that will be part of the ?07 Wrangler. This interesting system is engineered to monitor roll attitude and lateral force in order to detect a possible rollover. In the event that the system thinks a rollover may occur (we?re talking about asphalt speeds here), ERM can reduce engine torque and apply braking to prevent tipping over. Or so the theory goes. (Too bad they didn?t have this back in the CJ5 days!)
Chassis Design

We?re always biting our nails when a remake of a classic is on the board, and fingers were close to the mouth before getting the full look at the TK. Fortunately, the Jeep design team not only placed conservative hands on the CAD programs, they managed to improve the breed in many ways without compromising those essential Wrangler design elements we?ve come to love.

Yet as with anything open to subjective interpretation, what some may like others will gig mercilessly. We?re confident, however, that the ?07 Wrangler will quickly find a home in the hearts and garages of the Jeep brand faithful.

Much of the new design seems to follow a desire to minimize wind noise and improve aerodynamics. The flat, seven-slot grille is now slightly canted rearward, and the sealed headlamps and turn signal lamps exhibit a cleaner look. Most notable up front has to be the revised bumper. It?s a single-piece blow-molded unit (no more dislodging those annoying endcaps on the trail) featuring integrated fog lamps. Underneath is an air dam that should help the Wrangler?s aerodynamic profile, as well as cut some of the undercarriage wind noise. Big-time noticeable are the massive bolt-on fender flares, supposedly built to resist corrosion and denting better than the old version.

While the YJ and TJ models make great departures from the old CJs, one thing that never changed was the flat windshield. Well, that mold has now been broken. The ?07 Wrangler will have a slightly curved windshield for improved wind resistance and reduced interior wind noise.

Additional exterior changes worth noting include blow-molded step assists with a diamond-plate textured surface, rock rails (standard on the Rubicon) and revised taillamps.

Another cool twist is the three-piece modular hardtop. This bugger has individual removable panels above the driver and passenger sides, and another which covers the back half of the vehicle. Check it out here? (requires QuickTime 7.03 plugin). Or see the slide show here.
Driving Environment

Manufacturers have done a lot of crazy, tacky, tasteless stuff to truck and SUV interiors in the last few years. Happily, we can report that the new Wrangler did not succumb to wretched design excess. Oh, it?s plenty different, but nothing to turn away loyal fans.

The Wrangler lost a lot of its rugged charm when the TJ hit the scene, and the new TK has taken refinement to the next level. There?s a definite contemporary SUV flavor to the dash and instrument panel, but nothing to cry ?Foul!? over. It?s cleaner and sleeker, yet holds close to the pattern established with the TJ. Where it diverges most from its predecessor may be the door panels. They certainly exude more character than anything that has come before, however, part of that is functional. For the first time in a Wrangler, power windows and door locks are available.

The only thing we can say that looks kind of goofy is the dash-mounted tweeter speakers. They sit upright near the A-pillars, and kind of look?well?odd. It?s obviously a great position to enhance the vehicle?s sound stage, but? And speaking of audio, all radios are MP3 compatible thanks to an auxiliary jack located on the radio faceplate.

Dimensionally, the new Wrangler is more accommodating than the TJ, due in large part to the vehicle?s greater width. Driver and passenger shoulder and hip room is up 5.1 inches and 4.6 inches, respectively, and even backseat passengers benefit from marginal increases in shoulder and hip room, and an inch more leg room.

Another addition we like is the lockable under-floor cargo bin found behind the fold-and-tumble rear seat. Nice place to put a few essentials. As for the center console, it?s been updated with a centrally positioned parking brake handle, lockable storage bin, and front and rear passenger adjustable cup holders. Finally, the driver and passenger seats have a more sculptured, performance flair about them, which should be welcome when the trail gets a bit exciting.
Conclusion

Although we?re not able to provide you with the definitive assessment of the new-generation Wrangler until we get to wrap our grubby paws around the steering wheel and hit the road and trail, from what we?ve seen, Jeep division has played a cool hand in the TK?s development. From the specs it looks as if this Wrangler may exceed its predecessor in off-the-shelf off-road capabilities providing the increased wheelbase and track width doesn?t interfere with the kind of tight trail maneuverability short-wheelbase Jeep aficionados so love. As for on-road performance, there?s little doubt that the comfort and handling factor will ratchet up several notches. We are, however, disappointed in giving up the familiar 4.0L I6 in return for a V6 with such a marginal increase in power output. Not sure where the gain is here. Still, we?ll hold off any loud proclamations until a full field test comes available, and in the meantime salute DC for holding true to the Wrangler heritage.

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