Big cars with adequate gas mileage are hard to come by, but one of the best options at the moment is diesel power.
At its best, the BMW 7-Series has a high fuel consumption. With a turbocharged, 3.0-litre inline six, the best it can attain is 12.3 km/l on the highway.
Throw in a diesel engine though and it should improve – so goes the theory behind the latest addition to the range, the 740Ld xDrive.
The name is a bit of a mouthful–the ‘L’ stands for BMW’s long-wheelbase chassis, and ‘xDrive’ is BMW-speak for an all-wheel drive transmission.
But the ‘d’ is the important bit, since it refers to the car’s 3.0-litre, twin-turbocharged inline-six cylinder diesel engine. This develops 255 horsepower at 4,000 rpm and a useful 600 Nm of torque between 1,500 and 3,000 rpm.
All that grunt is filtered through an eight-speed automatic transmission and the aforementioned all-wheel drive system; 0-100 km/h acceleration takes just 6.1 seconds.
The biggest numbers should be the car’s economy, but there’s no official EPA figure just yet.
BMW points out that in other models equipped with the same engine, fuel efficiency has risen by 25 to 30 percent. With the BMW 535d for example, using the same six-cylinder diesel, combined mileage is 2.5 km/l better than the 10.2 km/l combined 535i.
If that trend continues, we can expect figures of around 10.2 km/l city, 15.3 highway and 11.4-11.9 km/l combined from the big Bimmer. Driving Dynamics Control with an Eco Pro mode and standard start-stop should help drivers minimize their fuel use too.
The 740Ld should be clean too, its exhaust gas treatment system is specifically designed to comply with ULEV II emission standards. A NOx storage catalyst, diesel particulate Filter and a Selective Catalytic Reduction (SCR) system all ensure harmful emissions are kept to a minimum.
All this technology doesn’t come cheap, pricing starts at USD $83,425, but owners will at least save on fuel. You will be covering the first glimpse of the car at next month’s Chicago Auto Show, deliveries begin Spring 2014.