2006 Jeep Liberty

The latest Jeep Liberty sport-utility vehicle with its turbocharged 4-cylinder diesel engine might be considered an alternative to gasoline-electric hybrid SUVs. Anyway, it's far more fuel-stingy than a Liberty with a gasoline V6, which is the only other engine offered for this vehicle.

Jeep says the Liberty's turbodiesel provides the torque of a V8, performance of a V6 and fuel economy of a 5-cylinder gasoline engine, although the Liberty V6 can outrun it—at a considerable cost in fuel economy.

The Liberty turbodiesel has a class-leading towing rating of 5,000 pounds and is covered by a 5-year/100,000-mile warranty.

Only Diesel In Its Class
The common-rail Italian-made turbodiesel (CRD) comes from an outfit partly owned by DaimlerChrysler, which produces Jeeps. The diesel replaces the Liberty's 4-cylinder gasoline engine and makes the Liberty the only vehicle in its class with a diesel.

Considering higher U.S. gasoline prices, the turbodiesel is the big news for the 2006 Liberty, which is arguably the slickest-looking Jeep.

Let's face it—the Jeep Wrangler looks like it's just pulled off a World War II battlefield and the new Jeep Commander resembles a big box. Only the Jeep Grand Cherokee might be considered as stylish as the Liberty, although it's not as cute.

More Diesel Torque
The 3.7-liter 210-horsepower Liberty V6 has it all over the 2.8-liter 160-horsepower turbodiesel when it comes to horsepower. But the turbodiesel provides considerably more torque than the V6—295 pound-feet at only 1800 rpm. Good torque long has been the mark of a good diesel.

The Liberty Diesel comes only with a 5-speed automatic transmission and four-wheel drive. It provides an estimated 22 mpg in the city and 26 on highways. It also has an estimated highway cruising range of 500 miles on a tank of fuel, which makes it among economy leaders in the midsize SUV non-hybrid class.

In contrast, the Liberty V6 provides 17-18 mpg in the city and 22-23 on highways. It comes with a 6-speed manual gearbox or 4-speed automatic transmission.

Two Liberty Diesels
The Liberty Diesel comes in the $25,290 Sport and $27,480 Limited Edition trim levels. Gas engine Libertys are offered in Sport, Renegade and Limited Edition trim levels and sell from $22,700 to $26,090.

Nearly half the cars have diesel engines in Europe, where diesel fuel costs less than gasoline, which is priced upwards of $5 per gallon.

Bad Memories
But Americans have bad lingering memories of General Motors' mediocre diesels, used in 1970s Oldsmobiles and Cadillacs that debuted during the U.S. fuel economy hysteria of the 1970s.

Modern European diesels are smooth, quiet and refined. But the GM diesels, which really were converted gas engines, were loud, smelly and provided lazy acceleration.

No GM car sold in America offers a diesel. But the Mercedes-Benz midsize E320 CDI sedan has a refined, sophisticated turbocharged 6-cylinder diesel with good punch. It delivers an estimated 27 mpg in the city and eye-opening 37 mpg on highways. (Many of the best diesels in Europe have 6-cylinder and V8 engines.)

European fuel-economy ratings give more weight to highway mileage, where diesels get much of their fuel economy advantage. Gas-electric hybrid vehicles are popular in America because the EPA's fuel economy rating procedures favor stop-and-go driving common in congested traffic.

Hybrids that shut off a gas engine at idle and rely on a battery power pack at lower speeds to keep moving thus gain major mpg numbers in those tests. They also generally get city mpg ratings that are higher than highway ratings, where their gas engines kick in to mainly propel them.

Liberty Improvements
The Liberty Diesel benefits from general 2006 Liberty improvements, which include a standard Electronic Stability System that consists of an anti-skid system with anti-lock brakes, traction control, electronic roll mitigation and brake assist for surer panic stops.

The Liberty Diesel provides decent in-town acceleration, but could use another 50 horsepower (couldn't we all?). The 0-60 mph figure for the 4,296 Liberty Diesel is average at 10.1 seconds and 65-75 mph passing is slow, even with just a driver aboard.

Still, the Jeep Diesel holds its own in city traffic and works well with its automatic transmission, which upshifts smoothly and downshifts quickly. Fast highway cruising is no problem.

Diesel Drawbacks
The Liberty Diesel isn't as quiet or refined as many European diesels. It has the mild clatter and vibration of older diesels and briefly emits smoke after being started when cold, although I noticed no diesel odor that lasted for more than a few seconds after the engine was started.

Jeep says the turbodiesel has large cylinders that create excessive noise and that the engine sits close to the passenger compartment.

Rock Solid
The Liberty feels rock-solid with either the smoother, quieter V6 or turbodiesel. Steering is good and handling is decent for a rather high SUV. The firm suspension delivers an acceptable ride on most roads, and any Liberty version has impressive off-road abilities.

Extra effort is needed to get in, but large outside door handles help and passengers sit high. Front seats should be larger and provide more side support.

Fairly Roomy
There's decent space for four 6-foot adults, although the large front console eats into occupant room, and a tall driver with long legs will wish his seat moved back farther. Knee room gets tight behind a driver who slides his seat back all the way.

Power window controls are inconveniently located near the rear of the front console. Gauges can be easily read, and the large climate controls work smoothly. But audio system controls are too small for easy driver use.

Front doors have storage pockets, while rear doors have bottle holders and windows that roll down all the way.

Large Cargo Area
The cargo door swings open to the left for easy curbside loading and its window pops open and out of the way when the tailgate handle is pulled. The cargo opening is rather high, but cargo space is good with the rear seat in its normal position and impressive when that seat is flipped forward.

There's no need for a bothersome prop rod because the hood swings up smoothly on hydraulic struts. It's easy to reach fluid-filler areas in the engine compartment.

The Liberty Diesel isn't for everyone. But, then again, neither are gas-electric hybrids. Moreover, diesel engines last nearly forever, and owners of this Jeep SUV can enjoy every mile of higher fuel economy.