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BMW’s “Me Too” Hybrids

Brad Berman — Thu, 20 Nov 2008 15:19:07 +0000

BMW presented a pair of hybrids yesterday—both packed with V8 engines—at the Los Angeles Auto Show. The old news is the BMW X6
full hybrid crossover, which debuted last year in Frankfurt. The new item is the BMW 7-Series mild hybrid concept, which promises a 15 percent reduction in fuel consumption.

Unveiling the 7-Series hybrid, Dr. Klaus Draeger, BMW board member, said, “What does that mean for customers? The highest level of efficiency in the luxury class combined with the best dynamic performance among hybrid vehicles.”

In other words, the company has stuck to its guns: no compromise in performance and a very modest improvement in fuel efficiency. It’s expected that the 7-Series hybrid will top out in the mid-20 mpg range on the highway—pretty good for a two-ton full-size vehicle. BMW is eking out this mileage by using a start-stop system, regenerative braking, and low rolling resistance tires.

The powerful twin-turbo 4.4-liter gas V-8 delivers 400 horsepower and 450 lb-ft. of torque with the 120-volt electric system adding some auxiliary power. The heart of the system is an AGM (absorbent glass mat) lithium ion battery pack stored in the trunk. An electric motor integrated into the transmission replaces the alternator and enables the start-stop system.

The BMW approach is similar to the one taken by Lexus with its LS 600h hybrid, using the hybrid system to boost efficiency, but not reducing engine size. BMW calls it Efficient Dynamics. What do we call this luxury vehicle with smidgen of hybrid-ness thrown on top? A half-hearted hybrid that’s out of step with the times.

The new non-hybrid BMW 7 Series arrives in the US in early 2009. The hybrid version remains a concept at this time.

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Hybrid Car Math, German Style

Brad Berman — Sat, 12 Apr 2008 18:05:47 +0000

German carmakers may sing the praises of hybrids when unveiling a new concept at a major auto show, but their tune changes about hybrid cars when they gather for an industry insiders’ event. The Germans almost unanimously maintain their long-held belief that hybrids just don’t add up when compared with diesels and next-generation gasoline vehicles.
Engineers from the German companies spoke at the VDA’s (the German auto industry trade association) 10th annual technology conference in Ludwigsburg on April 2, according to the trade magazine SupplierBusiness.

Volkswagen’s Dr. Jens Hadler, executive director of powertrain development, said that stop-start devices—a very mild form of hybridization which shuts down a gas engine when the vehicle comes to a stop—can give clear savings, but a car with a full hybrid system, like the Toyota Prius, is too costly. He estimated that while stop-start systems could save 3 to 5% of CO2 emissions, a full hybrid like the Prius would save five times the fuel, but at 18 times the cost.
Hadler sees this cost coming down with successive generations of hybrids, but not enough to make hybrids worthwhile in the future. This stance leaves little hope that Volkswagen will put its 70-mpg diesel-electric full hybrid Golf concept into production.

Franz Fehrenbach, CEO of Bosch, said that diesel hybrids, like the Golf concept, make even less sense than gasoline hybrids. According to Fehrenbach’s calculations, a gasoline full hybrid adds €2,000 to the cost of a car, but delivers only €1,500 in fuel savings over the first three years of the life of a vehicle. That’s a €500 loss over three years. The hole gets bigger with a diesel full hybrid, which adds €3,500 in cost but delivers €2,500 in savings, according to Fehrenbach.

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BMW's Mild-Hybrid Diesel Vision

Brad Berman — Mon, 25 Feb 2008 23:05:53 +0000

BMW will introduce a mild hybrid diesel concept vehicle—based on the BMW X5—at the 2008 Geneva Motor Show in March. The seven-passenger vehicle will utilize a 2.0-liter four-cylinder diesel engine with variable twin turbo, common rail injection—promising 36 miles to the gallon and 200 horsepower. The company calls the diesel hybrid, “BMW Vision EfficientDynamics.”

Many analysts believe that the economics of combining a diesel engine and a hybrid system—both of which add significant production costs—make diesel-hybrids a difficult proposition. “This is no pie-in-the-sky project,” said 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 hybrid system uses a 120V lithium ion battery. Electric assist comes from a 15kW motor paired up with an 8-speed automatic transmission. The lithium ion battery pack and system can support ancillary systems such as air conditioning when the engine is switched off at idle or stop. The BMW Vision EfficientDynamics also features aerodynamic wheel rim designs and a solar roof which acts as an additional energy source.

BMW is using a “modular” approach of mixing and matching various hybrid technologies, fuel sources and engine sizes. Last fall, at the Frankfurt Auto Show, the company showed the larger and more powerful X6 sport activity coupe—a full hybrid eight-cylinder gas-electric hybrid. These vehicles are concept studies, with no announced production dates.

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