Off-road people do things differently than on-road people. Off-roaders measure their tires by overall diameter; on-roaders measure theirs by wheel diameter and sidewall height. Off-roaders go slow, favor long-travel accelerator pedals, and rarely use brakes; on-roaders like a quiet wood-and-leather interior, balanced handling and quick-reacting brake and accelerator pedals.

Jeep's new fourth-generation Grand Cherokee speaks to both groups, with fluency in both languages. A lot of the new five-seat, two-row Grand Cherokee chassis is shared with Mercedes' next-generation ML-Class SUV – a byproduct of development that began under the DaimlerChrysler regime. So the new Jeep steers more accurately than previous models, takes big bumps more quietly, and handles rough roads more calmly. It's a significant improvement, and considering the Jeep retails for about $16,000 less than Mercedes' ML-Class, it's an astonishing value.

The Development Trail

The newest Jeep evolved internationally. Back in August 2006, Mercedes-Benz and Jeep were both owned by DaimlerChrysler, and design work began simultaneously on the new Grand Cherokee and the next Mercedes ML-Class sport utility. By the time Chrysler and Jeep were spun-off by parent Daimler-Benz, the design on the Jeep had been completed. Of course, Chrysler's independence didn't go so well, and after its 2009 bankruptcy became a part of Italian carmaker Fiat. In Italy, previous models of the Grand Cherokee sell for the equivalent of $60,000, and the vehicle is highly esteemed, so Fiat executives let the Jeep crew finish the job without interference.

Collaboration with Mercedes allowed the Jeep engineers to choose the best parts from each maker: The new Jeep and next ML-Class use the same engine cradle and suspension mounting points, and rear suspension design.

"This is a much better car because of our involvement with Mercedes than it would be had they not been involved," says Jansen. "The Fiat people respect Jeep and listened to us," he explains, adding that a new system of quality control during assembly, called "Meisterbar" measuring, was put in place at the Detroit factory, currently the only plant worldwide scheduled to build the new Grand Cherokee.

One For Everyone

The model lineup for the Grand Cherokee is familiar: A rear-drive Laredo model is priced at the starting MSRP of $30,215, and the two higher trim models are the Limited and Overland, which tops out at $41,120. The standard engine for each model is a new 3.6-liter double-overhead-cam V6 that makes a gutsy 280 hp (that's 65 hp more than the old 3.7-liter V6), as well as 265 lb-ft of torque. The optional engine is the familiar 5.7-liter V-8, which pumps out 360 hp and a stump-pulling 390 lb-ft of torque. A large 24.6-gallon fuel tank means that the range is a reassuring 500 miles.

The 2011 Jeep Grand Cherokee. Click on the above photo to see more images (Damon Lavrinc, Autoblog)

All models use a five-speed automatic, although the V8's make use of six actual ratios because of two second gears, one used when upshifting and another when downshifting. The base four-wheel-drive system is called Quadra-Trac I, and uses a single-speed, full-time transfer case. Optional is a two-speed Quadra-Trac II transfer case for serious off-road terrain, while V-8 models use a Quadra-Drive II two-speed system with a rear limited-slip differential.

The base Laredo is equipped with lots of standard features, such as 30.5-inch tires. (Those are 245/70-17's for you on-roaders.) The Limited comes standard with wider 18-inch tires (265/60's) while the Overland gets 265/50-20's. Standard on all models are tilt and telescoping steering wheels, wrapped in leather with controls for cruise and audio functions. Automatic headlights and power folding exterior mirrors are also included.

The new Grand Cherokee is about an inch longer than the previous model, yet its wheelbase is four inches longer, and almost all of the extra interior space is translated into rear-seat legroom. The seven-slot front grille is familiar, but now the headlights intrude a bit into the outer slots, a deliberate styling touch that's supposed to mimic the original military Jeep's front grille. Optional are double arc-discharge headlights, and in this case the standard halogen's inner lamps become daytime running lights instead of separate high beams.

The 2011 Jeep Grand Cherokee. Click on the above photo to see more images (Damon Lavrinc, Autoblog)

Inside, the trim, switches and materials appear high-quality, especially the standard leather that comes with the Overland model. We would prefer more places for passengers to grab when the car is off-road, although Jeep says extra "Oh God" handles would have interfered with crash impact tests. On the highway, the new Grand Cherokee is unexpectedly quiet. Jeep had developed double and triple layers of sound deadening to quiet the 2008 and 2009 diesel-powered model, and transferred that technology forward to the new 2011 model.

Speaking of diesels, in Europe, 70 percent of Grand Cherokees sold are diesels, equipped with the 3.0-liter Mercedes diesel engine that was available in the U.S. in 2008 and 2009. However, Jeep says the diesel would add a $6,000 premium to the cost of the newest Grand Cherokee here. According to Jeep chief engineer Phil Jansen, until gasoline is priced significantly more than diesel in the U.S., the small demand here is not worth selling a diesel.

Off-Road Enhancements

A new secret off-road weapon is standard on the Overland and optional on the other models: Air springs that will lift the Grand Cherokee a total of three inches above its normal eight-inch ground clearance. Two off-road settings raise clearance as well as center-of-gravity, allowing an off-road driver to tailor the car's height to the terrain. A park mode drops the Grand Cherokee 1.5-inches for easy entry, and an aero mode lowers the car 0.6 inches for better aerodynamics on the highway. The system works quickly and silently, fed by a scuba tank-size compressed air cylinder under the rear seats.

The 2011 Jeep Grand Cherokee. Click on the above photo to see more images (Damon Lavrinc, Autoblog)

In addition, Limited and Overland models come standard with a Selec-Terrain system that's similar to Land Rover's integrated stability, traction and braking functions. These are selectable by the driver with a knob corresponding to conditions like sand, snow, mud, and rocks, although there is also an automatic setting that will let the Grand Cherokee choose the best traction calibration.

Off-road, the latest Jeep Grand Cherokee is so capable that anyone can take the car on a black-diamond slope and look like a pro. It's what we call a "Point-and-Shoot" off-roader. We drove a Laredo and an Overland equipped with the air springs, and the composure of the Grand Cherokee was a new level of graceful.

A long drive on the highway showed the new Grand Cherokee is equally quiet and calm, with a ride befitting a luxury car. But when the going gets rough, the Grand Cherokee will literally rise to the occasion and step its way where cars and crossovers fear to tread.