Here's part of a very ineresting little article from Automotive News. I bolded some parts that I found particularly interesting:
The era of making engines bigger is over at BMW.
The German maker of high-performance vehicles will stop making engines bigger to boost performance. Instead, BMW will use turbochargers, more efficient valvetrains and advanced electronics to boost performance while increasing fuel economy.
[Senior vice president of powertrain development for BMW, Klaus] Borgmann outlined several ways BMW will boost fuel economy starting this fall.
BMW is spreading its Valvetronic system, which varies the duration and lift of the intake valves to maximize fuel economy, emissions and performance, to the 2007 Mini Cooper. The sporty S version of the British-made hatchback will use a turbocharger, instead of the supercharger in the current model, and have direct fuel injection, Borgmann said, for about a 10 percent fuel economy gain over the 2006 car.
Instead of bigger engines, he said, turbochargers will be used on other BMWs to improve performance.
In 2007, European BMWs will be equipped with a stop-start feature that turns off the gasoline or diesel engine when the car comes to a stop. The engine restarts immediately when the driver lifts his or her foot off the brake pedal. Borgmann said the feature is being evaluated for North America. Stop-start may not be suitable for hot climates, he said, because the air conditioning compressor stops working when the engine is off.
The stop-start system will use a specially modified starter, instead of a belt alternator system, and a heavier-duty battery. The Mini Cooper also will have the stop-start system.
A new alternator management system BMW calls Brake Energy Recuperation makes more efficient use of the car's charging system. The goal is to capture some of the energy normally lost when a car is braking. Borgmann said the system keeps the battery charged at 80 percent to reduce the load, or drag, that the alternator places on the engine while the vehicle is cruising.
When the driver applies the brakes, a sensor commands the alternator to produce a short blast of electricity to bring the battery up to a 90 percent charge. When the driver accelerates, the alternator is allowed to spin freely so no drag is placed on the engine. BMW will begin installing the Brake Energy Recuperation systems in 2007 on European market vehicles, along with stop-start.
This is certainly exciting news, especially coming from a company that does not have a particularly good record on fuel economy. (BMW is one of the few manufacturers that consistently chooses to flout Corporate Average Fuel Economy standards, instead paying fines for missing the targets) It’s all the more exciting since it’s being offered on the Mini Cooper - a car in which my fiancée has demonstrated an inordinate amount of interest.
This is a good example of how an automaker can put conventional technologies to work to improve fuel economy while maintaining the safety and performance their customers expect. Of course, we can’t miss out on a chance to point out that if it were GM building this car, they’d probably try and pass the product off as a hybrid...
So kudos to BMW for promising meaningful increases in fuel economy, and not trying to claim more than their due!
Posted by: Don