The 1999 Jeep Grand Cherokee and its new V8 engine.

The 1999 Jeep Grand Cherokee is offered with two all-new powertrains in addition to an improved 4.0-L inline six-cylinder engine. At the top of the lineup is the 4.7-L V8 PowerTech engine, but vehicles for markets outside the U.S. will also be available with a new 3.1-L five-cylinder turbodiesel engine. Chrysler says that advanced design technology, state-of-the-art materials—and, in the case of the 4.7-L engine, an all-new manufacturing facility in Detroit—ensure that the engines meet or exceed customer expectations of power, fuel efficiency, quietness, emissions, serviceability, and durability. Vehicles assembled in Graz, Austria will also be available with the new turbodiesel built by VM Motori in Cento, Italy.

"We chose to design these new engines with optimum displacements that would maximize fuel efficiency and minimize emissions, while setting a new level for performance and refinement," said David Van Raaphorst, Executive Engineer - Powertrain. "For the V8, it meant a smaller displacement, but more usable power; less noise, vibration, and harshness; and greater durability than the 5.2-L engine it replaces. For the turbodiesel, it meant that we added a cylinder and more displacement to meet the demand for added performance in our international markets.

"Engine efficiencies were key goals in the development of these engines," added Van Raaphorst. "With the extensive use of alternative materials plus our ability to optimize the airflow by using computer simulations, we have engines that produce more power, use less fuel, and burn cleaner than the engines they replace. By increasing engine and overall powertrain stiffness, improving the balance of rotating components, and upgrading the powertrain mounting system, we have made this engine among the most quiet, refined, and best sounding gasoline powerplants Chrysler has ever developed."

From the beginning, key design and engineering objectives for the new PowerTech V8 were improved performance, efficiency, refinement, durability, and lower emissions. With roughly 10% less displacement than the 5.2-L V8 in the previous Grand Cherokee, the new engine has 7% more power, an estimated 1 mpg better fuel efficiency, and 30% less emissions. The 4.7-L engine complies with California's Low Emission Vehicle (LEV) standards.

The new V8 engine features a tuned-length-runner intake manifold, freer flowing intake and exhaust ports, and fast burn combustion chambers.

The new engine has a cast iron block and cast aluminum cylinder heads with a single overhead camshaft per bank. A relatively small bore of 93 mm (3.66 in.) helped reduce overall engine length, facilitating packaging in the compact engine bay of the Grand Cherokee. The stroke is 86.5 mm (3.4 in.).

Power output is 175 kW (235 hp) at 4800 rpm in Tier 1 U.S. and European Stage II emissions standard versions. The California LEV version of the engine has emissions reductions of about 30% from Tier 1 levels. Versus the 5.2-L engine, it gains 7.5 kW (10 hp) to 172 kW (230 hp), with maximum torque of 400 N•m (295 lb•ft) at 3200 rpm.

The new engine features a tuned-length runner intake manifold, freer-flowing intake and exhaust ports, and fast-burn combustion chambers for optimum breathing and combustion efficiency. Though it operates with a high 9.3:1 compression ratio, the engine requires only regular-grade fuel, which directly translates into cost savings for the customer.

Lightweight material applications and more efficient accessories (alternator, power steering pump, air conditioning compressor) help to improve vehicle performance and fuel efficiency. Aluminum cylinder heads, hollow camshafts with sintered steel lobes, magnesium valve covers, a molded composite intake manifold, and accessories directly mounted to the engine structure contribute to an overall reduction of 24 kg (54 lb) compared to the 5.2-L engine.

The Grand Cherokee's 3.1-L turbodiesel produces nearly 20% more power than the 2.5-L engine it replaces.

Driveability is enhanced by variable fuel-injection timing, sequential multiport injection, a quick-sensing inlet-side positioned thermostat, and coil-on-plug ignition. For improved fuel efficiency, the engine features a patented, hybrid-cooling system that combines inline electric and engine-driven fans. This system allows the engine fan to idle at a lower speed (250-300 rpm vs. a typical 650-700 rpm), decreasing noise and vibration. The cooling system uses a high-efficiency water pump, and a secondary thermostat control reduces power consumption by 12% or 4.5 kW (6 hp).

The engine is designed to operate 240,000 km (150,000 mi) under normal conditions without part replacement other than normal maintenance items. An automatic, serpentine belt tensioner increases average accessory belt life to 160,000 km (100,000 mi).

The new turbodiesel engine provides nearly 20% more power and torque than the 2.5-L unit it replaces, delivering up to 12.5% better acceleration, a higher top speed, and more load-carrying and towing capacity. Its fuel system uses full electronically controlled diesel injection, and a drive-by-wire "electronic accelerator" is employed.

The 3125-cm3, inline turbodiesel with intercooler has a bore of 92 mm (3.62 in.) and stroke of 94 mm (3.70 in.). It has a cast iron block and cylinder head with two valves per cylinder. The preliminary power rating, with a 21:1 compression ratio, is 112 kW (150 hp) at 4000 rpm, with torque of 373 N•m (275 lb•ft).

"Diesel engines power Grand Cherokee's success in international markets," said Dick Winter, general manager of international product planning. "One third of all Grand Cherokees sold outside North America are equipped with a diesel engine. We expect this to increase with the new vehicle and the new engine." The 1999 Grand Cherokee is the first turbodiesel-powered Jeep vehicle with a standard automatic transmission, reaffirming the upscale positioning of the new Grand Cherokee in international markets.