The March of Progress
Published: 09/13/2011
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by
Jason Kavanagh, Engineering Editor
If you think the eggheads in Stuttgart labor over every change to the Porsche 911, imagine what the Jeep guys go through when it comes time to take the scalpel to the Wrangler.
Traditionalists, being traditional, loathe change, and the 2012 Jeep Wrangler entails the plucking of the Wrangler's very beating heart for a new and improved unit. You can almost hear the traditionalists gasping for air.
One run through the gears of the 2012 Jeep Wrangler is all that's needed to prove that the traditionalists can relax. There's nothing to worry about. In fact, there's plenty to be excited about.
New Engine, Transmission
To soften the blow of too many changes all at once, the caretakers of America's most cherished trucklike thing spread them out over two model years. OK, that's kind of a lie. In reality, the Wrangler's 2011 cabin tweaks were originally thought to be accompanied by a powertrain upgrade, but the vagaries of manufacturing postponed the heart transplant by a year. So the 2012 Wrangler essentially completes phase two of the model refresh that started with last year's model.
Headlining the changes for 2012 is the adoption of Chrysler's DOHC 3.6-liter Pentastar V6. It kicks out 260 pound-feet of torque at 4,800 rpm and 285 horsepower at 6,400 rpm, some 23 lb-ft and fully 83 hp more than the old-school pushrod 3.8-liter V6 it replaces. For some perspective, the Pentastar generates more torque at 1,900 rpm than the outgoing engine produced at its peak, and continues making meaningful grunt all the way to 6,400 rpm.
Sheer output isn't everything, and to ensure Jeep-worthiness, the Pentastar received some tweaks. Wranglers need to be able to ford water that's 30 inches deep, so the alternator was relocated to the top of the accessory drive. A deep-sump oil pan and pickup was fitted to ensure reliable lubrication while crawling up ridiculous grades, and a rejiggered intake tract improves torque output.
All told, the new engine is 3.7 inches shorter in length and 90 pounds lighter than the old 3.8-liter mill, though the weight savings is largely offset by the new, beefier automatic gearbox. Yes, for 2012 the Wrangler's four-speed automatic has been consigned to the dustbin of history. In its place is the A580 five-speed autobox that backs Chrysler's Hemi products including the Jeep Grand Cherokee. The six-speed manual gearbox is carried over and remains standard equipment, along with a low-range transfer case.
With the new gearbox ratios and a taller standard axle ratio of 3.06, the automatic-equipped 2012 Jeep Wrangler's overall gearing is now a touch shorter in 1st and a smidge taller in top gear.
Save for a few bits and baubs, the rest of the Wrangler's hardware carries over essentially as is.
Nobody Will Miss the Old Engine
Turned loose on the billiard table-smooth blacktop outside of Portland, Oregon, the reinvigorated Wrangler is more enthusiastic, and the autobox is more likely to have the right gear for the occasion. This is still a near-4,000-pound truck with the aerodynamic profile of the Parthenon, so those hoping the Wrangler has been transformed into a tire-fryer might be disappointed.
The numbers are encouraging, though. Zero-to-60 drops to 7.7 seconds for the two-door Wrangler (8.4 for the four-door), compared to 10.4 for the 2011 model. In practice the engine's flat torque curve masks the rate at which speed rises, making its urgency feel appropriate, rather than the old engine's asthmatic.
The net effect of more grunt and another gear is less hunting between gears on freeway grades, too. It's an incremental improvement, as the gearing is still rather tall. The move to five gears might be a big deal to Jeep guys, but this is one application where a six-speed autobox wouldn't be a bad idea.
Jeep officials were proud of the new engine's improved NVH characteristics. When cruising, you'll be hard-pressed to hear a difference, as wind noise still dominates everything else that makes noise, including the engine. But when you give it the spurs, the new engine makes better sounds than the old lump.
The steering remains recirculating-ball type, and it remains hilariously ropey on pavement. It's nonlinear, lacks feel and exhibits significant yaw delay. With live axles front and rear, the ride bucks and shudders over pavement imperfections. Refined and honed as it has become over the years, driving a Wrangler is still kind of like driving a forklift. Call it part of the charm of the thing, along with being able to fold the windshield down and remove the doors, which is too cool for words.
Still a Wrangler
Wait, this is a Jeep, right? All this talk of pavement and NVH and efficiency and steering feel might have you wondering where their priorities are. Not to fear. The Jeep staff insists that all the changes that improve the Wrangler's day-to-day livability will never compromise its off-road capability.
As if to prove it, part of our drive of the 2012 Jeep Wrangler included stints in the off-road-focused Rubicon model up a trail that was crafted to show off the depth of the truck's talents. To the uninitiated, the path would appear impossible, yet the Wrangler crept up and down the steep, rocky, log-strewn, rutted pass littered with sinkholes the size of Kias without even breathing hard.
Though the electronic throttle calibration doesn't always provide instant response, there's ample torque down low in the new engine. It runs cool, too, thanks in part to a new variable-speed 600-watt cooling fan and a larger A/C condenser and transmission cooler. Hell, the A/C didn't even flinch in the hot weather no matter how slow we crawled. The Wrangler remains a staggeringly capable off-road steed.
No Compromise
Imagine, all that added capability and the 2012 Jeep Wrangler even burns less fuel. Yes, its EPA fuel-efficiency numbers are now 17 city/21 highway mpg for two-door models, a 2-mpg bump up last year's numbers.
All that, and Jeep held the line for pricing of base models, while the MSRPs of high-zoot Sahara and Rubicon models swell by just $300.
It's like having your cake, eating it, and then finding out it lowers your cholesterol, too. Even traditionalists will have a hard time arguing with that.
Edmunds attended a manufacturer-sponsored press event to facilitate this report.
