Don't let that cute, wide-eyed look fool you. The newest addition to one of America's oldest off-roading portfolios is a Jeep off the old block. We took it through deep mud, over sump-rippin' rocks, across a pile of horizontal telephone poles, and, when cooler heads were turned, up a flight of concrete steps. Given its civil street manners and modern chassis/powertrain/suspension, it's impressively stout and readily climbs to heights many car-based SUVs fear to tread (see our Rubicon Trail sidebar for proof of that).

The new Jeep Liberty (internally dubbed the KJ platform) is intended to expand its reach to SUV buyers who place a higher value on on-road manners than off-road ability. Initially, its duty was simply to replace the boxy, taut-riding Cherokee, which debuted in '84. Instead, production of the old classic was extended because of continued strong sales. That also meant the Cherokee name was still on the old rig, so Jeep couldn't use it on the new one; hence, the Liberty badge.

We were quite surprised at the interior's high level of fit and finish in what should be a high-value street and serious
off-roading package.

Jeep's all-new 3.7L V-6 features a rugged truck-style design with a cast-iron block and light, aluminum heads. Our acceleration tests on an early engineering vehicle indicate an eager, if noisy, 210 hp. A balance shaft helps smooth its high-rpm vibrations.

Jeep calls its new-from-the-ground-up foundation a "uniframe." We call it a terrifically rigid, quiet unibody that employs lots of high-strength steel in its longitudinal rails, A-pillars, roof structure, and footwells for crash protection. Like the original Cherokee and Wagoneer, this new Jeep doesn't rely on a separate, heavy ladder frame for strength and road isolation as do some larger competitive models, such as the Ford Explorer and Chevy Blazer. Instead, like the Acura MDX and a host of new-gen off-road vehicles, it features hefty sheet-steel rails welded directly to the unibody's belly for beaming and torsional strength. With Jeep's almost two decades of experience in these designs, it should prove solid, even if regularly asked to twist its way over rough terrain.

There are two engine choices: a standard 2.4L DOHC four and a new 3.7L SOHC V-6 derived from the Grand Cherokee's 4.7L V-8. Thanks to twin balance shafts, the four cylinder is a well-behaved design that produces 154 hp and 167 lb-ft of torque-this engine is also used in the Chrysler PT Cruiser. Tranny choice with the I-4 is limited to a five-speed manual that can be teamed with either two- or a part-time Command-Trac four-wheel-drive systems. If you opt for the premium V-6, you can have a five-speed manual or a four-speed auto. V-6 models also may be ordered in two-wheel- or premium Selec-Trac four-wheel-drive form. As expected, Selec-Trac-equipped Libertys pack a dual-range transfer case.

The new 3.7L is good for 210 hp at 5200 rpm and 225 lb-ft at 4000 rpm. Conceived from the start as a truck powerplant, the six uses a heavy crank and bigger crank bearings than a car engine. It also features a rugged cast-iron block and SOHC aluminum heads with durable chain-driven cams. Because it's a 90° block, it also requires a balance shaft. Our test data says this V-6 provides decent motivation. But our preproduction test vehicles didn't offer an especially sophisticated sound or feel.

Liberty's front and rear suspensions are relatively sophisticated, however. The front is a fully independent short- and long-arm arrangement sprung with a coil-over shocks. With its extra-big rubber bushings, this beefy apparatus is good at sucking up road joints and potholes. It also works well in concert with the standard rack-and-pinion steering, which is nicely weighted and accurate. Out back is a hefty "three-link" live-axle with coils. Similar to the axle used in the bigger Grand Cherokee, it provides a supple street ride and articulates amazingly well over broken terrain-but the penalty is a fair amount of body lean.

Like most sport/utilities, the Liberty tends toward initial understeer-that's just the nature of vehicles with a high center of gravity, soft springs, and high-profile tires. At the limit (and beyond), it can be provoked into an oversteer condition, but a quick flick of the steering wheel brings the tail end back into line. Considering its modest grip levels, the Liberty's roadholding is average enough for an SUV, but no better. The same could be said for its braking capability: Anti-lock-assisted panic stops are quite stable, but a tad longish (though remember, we were testing prototype vehicles). Still, the Liberty offers more than acceptable on-road manners, considering its serious off-highway credentials. Just don't expect to toss it around like a Miata.