It's A Great Time For
Great Mileage
As more and more people in the United States become interested in fuel economy-even if the prices
we pay here are nothing compared with what Europeans pay at the pumps-the decision by Jeep to bring
in a diesel version of its Liberty SUV is pretty smart thinking. SUVs are the most egregious gas
guzzlers you can buy, so if you can still provide reasonable fuel economy and maintain SUV virtues
such as a high seating position and all-around versatility, what's not to like?
The Jeep's 2.8-liter, four-cylinder, DOHC, sixteen-valve, direct-injection, common-rail turbo-diesel
clatters at idle and has that proverbial hum at freeway speeds (we love it). The diesel provides
mighty torque and makes up for its modest power output.
This new unit displaces 2.8-liters in an inline-4 configuration. Power is rated at 160 hp. at
3,800 rpm and 295 lb.-ft. of torque at 1,800 rpm. With a 20.5 gallon tank and fuel economy
estimated in the mid 20s predictions are for 22 city/27 highway, which compares to the gasoline
Liberty at 20/24) and a driving range of close to 500 miles. Notable is an impressive 5,000 lb.
of towing capacity, a result of the torque. (This is 2 and _ times the capacity of the 4-cylinder
gasoline-engined Liberty and equal to the 6-cylinder version, which gets 17/22 fuel economy, by
comparison.)
Fuel is delivered to the cylinders via direct injection at up to 24,000 psi. The
injectors now burn fuel more efficiently, thereby reducing hydrocarbon emissions. Compared to
diesels of the 1980s, this engine is approximately 60 percent cleaner.
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Diesels have also been criticized for their sluggish performance. Subsequently, Jeep has attached
a turbocharger to provide the needed boost. A moveable vane inside varies the impact of the turbo
Ð during launches
it acts like a "small" turbocharger and increases low-end torque, while at higher revs it works
like a "large" turbo and provides top-end power. The new 2.8 is also quick to start, needing only
two seconds to warm up the ceramic glow plugs.
We drove the new model on a somewhat rigorous
"101 Off Road" course. Notable was its engine braking on steep hills and its overall handling,
typical of other Liberty's.
All diesel engines are backed by a 5-speed automatic transmission
with overdrive. Other engine options include a 150-hp. 2.4-liter inline-4 and a 210-hp. 3.7-liter
V6, both powered by gasoline.