BMW is setting out to silence critics of big, gas-guzzling SUVs with a new diesel-hybrid-powered X5 concept that it claims is as economical and clean-running as a modern sedan.
The seven-seat X5 Vision concept will be unveiled at next week's Geneva motor show. It's the latest installment in BMW's Efficient Dynamics program, which highlights the reduction in consumption and CO2 emissions expected when all of BMW's future driveline, electrical and aerodynamic developments are brought together in one vehicle.
BMW says the X5 Vision gets 36.2 mpg and produces 172 g/km of CO2--more than 6 mpg and 42 g/km better than the most environmentally friendly X5 on sale today, the 235-hp, turbocharged, 3.0-liter inline-six-cylinder diesel 3.0d. The X5 Vision carries an advanced hybrid drivetrain that BMW is already testing in various prototypes on German roads. It plans to introduce the powertrain in upcoming models such as the new X6 and the 5 Series-based Progressive Activity Sedan. BMW also hints that a production version of the X5 Vision may arrive soon.
"This is no pie-in-the-sky project," says Klaus Draeger, head of development at BMW. "All of the features are production-feasible. We could easily and without too much delay apply the various technology featured on our latest concept to existing showroom models." The X5 Vision's powertrain is different from the full hybrid system unveiled on the X6 ActiveHybrid at last year's Frankfurt show. The X5 Vision's powertrain is a mild hybrid with a diesel engine supplemented by an electric motor.
At the heart of the powertrain is BMW's latest twin-turbocharged, 2.0-liter, four-cylinder, common-rail diesel engine--used in the European-market 123d. With an aluminum block to keep weight over the front axle low and a third-generation injection system operating at 29,000 psi of pressure, it kicks out an impressive 204 hp--a bit more than 100 hp per liter--along with 295 lb-ft of torque at 2000 rpm. An electric motor mounted inside the transmission housing develops 15 kilowatts and a maximum 155 lb-ft of torque. The hybrid system uses regenerative braking to feed electricity to a lithium-ion battery pack stored underneath the cargo floor.
The X5 Vision is equipped with all-wheel drive. It uses an eight-speed automatic transmission--with the generator and electric motor management incorporated into the housing--engineered with ZF. The result is the sort of fuel economy and emissions ratings you'd normally associate with the 3 Series rather than the X5.
Along with the new hybrid driveline, BMW has applied a whole range of features to the X5 Vision to optimize efficiency further, including a stop/start function. Another development is the appearance of two distinct electrical systems. In addition to the conventional 12-volt system, the X5 Vision also uses a 120-volt arrangement. BMW says the two systems, which operate in parallel, help provide a more stable network than the traditional 12-volt system alone, allowing high-power systems to draw electricity more rapidly. The X5 Vision also has a large solar panel on its roof. It produces electricity and sends it to the battery, where it is then used to preheat the engine oil, while providing an immediate source of power for the air-conditioning, cool-box, entertainment and other systems when the car is stationary.
While BMW has not made any big changes to the X5's exterior for the concept, it has given it a new set of low-drag wheels. Developed in BMW's wind tunnel, the wheels have specially designed vanes that BMW claims reduce buffeting within the wheel wells. The wheels are fitted with low-rolling-resistance tires from Firestone.
No comments:
Post a Comment