BMW ActiveHybrid X6August 18, 2009
BMW has made huge progress with lowering emissions over recent years, but the company still has no full hybrid – until now, in the form of the ActiveHybrid X6.
The world premiere of the production versions of the BMW ActiveHybrid X6 – and the ActiveHybrid 7 (a 7 Series) – will be at the Frankfurt Motor Show in September.
Perhaps not surprisingly, the approach of BMW is not unlike that of Lexus – rather than going for out-and-out economy, the firm is aiming for the hybrid system to enhance the car’s driving performance. In fact BMW claims that this will be the world’s most powerful hybrid.
That’s the good news in summary. The bad news is that BMW does not see sufficient demand to bring either the ActiveHybrid X6 or the ActiveHybrid 7 to the UK at the moment as the vast majority of these cars that are sold here are currently diesel.
The full hybrid ActiveHybrid X6 offers a 20% reduction in fuel consumption compared to the petrol version, and CO2 emissions of 231 g/km.
It comes with a 400 hp twin-turbocharged V8 petrol engine and two electric synchronous motors, resulting in a maximum system output of 480 hp. This means acceleration from a standstill to 60 mph in 5.4 seconds. The top speed is limited electronically to 130 mph.
BMW’s xDrive all-wheel-drive system distributes the power between the front and rear axles.
The two-mode active transmission is based on an ECVT (electric continuously variable transmission) operating in two separate modes. One mode is for stop-and-go driving and low speeds, and the second is for driving at higher speeds.
However it has seven total effective gears in the automatic transmission, which the driver can also operate manually.
From standstill and at low speeds, only one of the two electric motors is activated. As soon as the driver requires more power or increased speed, the second electric motor automatically starts the combustion engine. The second electric motor then serves as a generator to provide a supply of electric power to the vehicle systems.
BMW’s first full hybrid model is able to run exclusively on electric power up to a speed of 37 mph, with a maximum range of 1.6 miles, with the petrol engine being activated automatically whenever required. When driving steadily at a higher speed most of the power required is delivered by the petrol engine.
In comparison, the ActiveHybrid 7 isn’t able to run on electric power only.
Energy storage is provided by a NiMH battery pack positioned beneath the floor of the luggage compartment, but storage capacity is not reduced.
On brake application and/or on deceleration, kinetic energy is converted into electrical energy and is stored in the battery pack. To provide this function either one or both of the electric motors act as a generator, feeding electric power generated back into the high-voltage battery.
The ActiveHybrid X6 will be available in America by the end of this year.