Timing, they say, is everything. And with everything that's happened to gasoline prices this year, the timing is indeed right for the introduction of the 2005 Jeep® Liberty
with a 2.8-liter turbo Common Rail Diesel (CRD) engine.
The engine is a technologically advanced powerplant with the torque of a V-8, the acceleration of a V-6 and the fuel economy of a four-cylinder engine. It is designed to be an efficient, smooth-running engine that produces lower carbon dioxide (CO2) emissions without sacrificing performance.
"The 2.8-liter CRD is among today's advanced diesel engines that emit 60 percent less emissions than diesel engines of 20 years ago," said Craig Love, Vice President - Rear Wheel Drive Product Team and Core Team Leader. "Additionally, the noise, vibration and harshness issues that plagued older diesel-powered vehicles have been dramatically reduced in the Liberty diesel. The result is that the legendary capability of the Jeep Liberty reaches a new level of performance with the 2.8-liter diesel engine."
The Jeep Liberty is the first mid-size sport-utility vehicle available with a diesel engine in the U.S. The 2.8-liter CRD boasts three best-in-class stats: 295 lb-ft of torque (400 Nom) @ 1,800 rpm; driving range of approximately 500 miles; and towing capacity of 5,000 pounds. The engine produces 160 horsepower and gets an estimated fuel economy of 22 miles city and 27 miles highway.
The 2.8-liter CRD is an enhanced version of the four-cylinder diesel engine currently offered on this vehicle in Europe. VM Motori, which is owned in part by Detroit Diesel, a DaimlerChrysler company, is the manufacturer of the engine. VM Motori has been supplying the Chrysler Group diesel engines since 1992 for minivans and Jeep products sold in Europe.
The 2.8-liter diesel uses an advanced common rail direct injection fuel system. Direct injection of fuel into an open combustion chamber is more efficient than a pre-chamber indirect injection configuration. The system in the 2.8-liter CRD operates at fuel pressures nearly 70 percent above the older distributor pump systems, producing finer atomization, leaner combustion and higher power. At the same time, direct injection provides inherently lower engine-out hydrocarbon exhaust emissions and lower NOx emissions. A high pressure pump driven by the cog belt from the camshaft supplies fuel at up to nearly 24,000 psi. The pump's electronic control system responds to fuel demand and delivers the optimal fuel pressure, injection timing and injection duration.
Injectors on the 2.8-liter diesel have been improved so that fuel burns more thoroughly, producing fewer particulates and lower emissions than previous generation diesel engines.
An electronically controlled variable geometry turbocharger improves control of boost pressure, reducing emissions and improving full load engine power and torque. The turbocharger features moveable vanes that allow it to act like a small turbocharger under launch conditions. At higher engine speeds it acts like a larger turbocharger. The benefit to customers is enhanced low-end and high-end torque. Meanwhile, a vacuum reservoir improves cold launch performance by allowing the turbo to spool up faster from idle, which minimizes turbo lag.
The Liberty diesel engine uses two pilot injections prior to the main injection. This system prepares the cylinders for the main injection of fuel, which helps to smooth out the main combustion and quiet the engine, especially at idle.
In another improvement, the 2.8-liter diesel uses electronically controlled ceramic "smart" glow plugs with a warm-up time of only two seconds. They assist with low ambient temperature start conditions and only glow when needed. This is an advance over older, timer-operated glow plugs that require up to 10 seconds of warm-up prior to engine start.
Six-Speed Manual Transmission
The 2005 Jeep Liberty features the NSG370 six-speed manual transmission, replacing two, five-speed manual transmissions previously used - the NV1500 and NV3550.
This new transmission is a member of the six-speed NSG370 family, similar to the one used in the Chrysler Crossfire, the first six-speed for the Chrysler brand. The NSG six-speed manual transmission provides a 4.46:1 first-gear ratio, versus the 3.85:1 and 4.04:1 ratios of the five-speed transmissions it replaces, for improved launch and traction. It also provides close-ratio gear performance in the intermediate gears.
The NSG370 six-speed manual transmission provides optimal shift quality, improved quietness and high quality. A new dual-ratio transmission shift-tower system allows packaging of the six-speed shift pattern within the existing Jeep vehicles, and is tuned for optimized shift quality.
For smooth operation the first and second gears have triple-cone synchronization, the third and fourth gears feature double-cone and the fifth and sixth gears single-cone synchronization. Hard-finished gears allow for quiet operation. A multi-rail, steel-construction shift system delivers high strength and precision. The two-piece aluminum case with integrated clutch housing assures powertrain stiffness and light weight. The new first-gear ratios combined with six-speed step spread allow optimization of axle ratios for fuel economy and performance.
The Jeep version of the NSG370 transmission has passed the rugged durability testing required of all Jeep driveline components.