This is the BMW I wanted to drive, not the hyped-up Hydrogen 7. I first saw a BMW 535d more than a year ago in the back shop of Gale Banks Performance. The car was the diesel-tuner’s facility for research and evaluation but wasn’t available for a spin around the block during my visit.
The guys in the shop, however, were nearly speechless with regards to its performance. Fast-foward to the LA Auto Show and BMW announces it will offer performance diesel engines in North America, starting in 2008. BMW did not reveal which engines or vehicle models will be introduced. One has to expect, however, that the 535d in some form will be one of the first. The move comes as BMW says its Advanced Diesel will meet the strict 50-state emissions standards. Nearly 70 percent of BMW sales in Europe are diesels, so consumers must demand that their BMWs be as fast as they are clean. A 535d was available as part of the Green Car Journal magazine’s ride-and-drive of environmentally friendly vehicles during the show. Test drives lasted only a few minutes around downtown Los Angeles. While I made arrangements to follow up with longer test drives on other vehicles, this car is headed back to Europe. That’s a shame because it gets 35.3 mpg. The 530xi now sold in the states is rated by the EPA at 27/20 with a combined rating of 22 mpg. Continue reading test report after the break and view photos of the unique twin-turbo technology. The 535d has all the luxury trappings of a BMW 5-series, and the diesel doesn’t interfere with the comfort. If you listen real hard you can detect diesel ping occasionally but the outside exhaust note doesn’t give away much. With 391lb-ft of torque available at just 1,500 rpm, a silky-smooth 6-speed automatic transmission and a 50/50 weight balance, getting away from the stoplight is an impressive exhibition. BMW says 0-100 km/h or 62 mph takes just 6.5 seconds.
Mashing the throttle for quick bursts was the limit of my test opportunity but that was enough to convince me that there is no loss of performance with this diesel. The 3-liter inline six engine features a variable twin-turbo system designed to eliminate turbo lag at low rpm and provide added boost at higher rpm. The smaller of the two turbos is mounted very close to the cylinder head so it can spool up quicker. The larger turbo is mounted out of the way. Based on engine speed, a series of valves diverts the airflow from one or both of the turbos. Both turbos will spin at low rpm but only the small turbo actually works hard enough to provide boost.
As the engine speed picks up, the larger turbo gets more exhaust flow, therefore it spins faster and can start compressing air that is then directed to the small turbo for additional compression. Finally, as the engine really gets up to speed and large turbo is working at maximum boost, the smaller turbo is cut out of the system. Another valve regulates the total boost.
The engine is rated at 272 horsepower at 4,400 rpm with peak torque of 413 lb-ft at 2,000 rpm. Now that many wealthy consumers drive 1-ton diesel pickups to tow their RVs and horse trailers, there shouldn’t be so much of a stigma attached to diesels in the luxury market. I’m quite sure if anyone has a doubt as to the performance and comfort of a diesel car, the 535d will cure them of any apprehension. If this vehicle was already available, the gas savings would be tremendous to consumers. Bring it here, fast.