You may be asking yourself: why would a bunch of diesel pickup owners be driving a European luxury sedan? Well, if someone told you it had a twin-turbo V-8 diesel cranking out 553 lb-ft of torque, would it change your mind? It changed ours! That, and the fact that Bosch, the company that has arguably done the most to advance and improve the use of diesels worldwide, loaned us the car.
Although it's not available in the United States, this European-spec version of BMW's 745d represents everything that could be in America-should the demand for diesels continue to increase-and was loaned to us for a taste-test of sorts. Although laced with today's typical emissions equipment, BMW claims its 4.4L twin-turbo V-8 cranks out 330 hp and 553 lb-ft of torque at the flywheel, can propel the 21/2-ton sedan from 0-62 mph in 6.6 seconds and is capable of nearly 33 mpg on the highway. With all this in mind, we set out to see if this sleek, diesel-powered four-door was capable of backing up those numbers.
Finicky On The Dyno
The biggest drawback of having a vehicle loaded up with all the latest technologically advanced gadgets is the fact that it might rely too much on its own electronics. During our first dyno test at Yimi Sport Tuning in Santa Clarita, California, the car entered a limp mode that was anything but subtle. First, every warning light on the dash illuminated, and the navigation display told us that every braking and steering function on the BMW had failed-or was going to.
Our initial conclusion was that, since the car had speed sensors on each wheel, it had sensed the front wheels weren't spinning and went into some sort of fail-safe mode. Still, the BMW managed to produce 250 hp and 465 lb-ft of torque, but since the car was clearly unhappy-we felt the German diesel might have more in it if we could only find a way to test it properly. Once we left the dyno, warning lights still illuminated, we had no power steering and minimal power. It was as if the BMW had gone into fight-or-flight mode and was protecting itself. Then, the car slowly came out of it, and went back to normal-no check engine lights or warnings displayed, and the power steering assist was regained.
Two days later, K&N Engineering's Tim Stewart invited us to test the 745d on K&N's state-of-the-art all-wheel-drive SuperFlow AutoDyn 30 AWD chassis dyno. Strapped to the rollers in Riverside, California, the 745d laid down a best of 264 hp and 480 lb-ft of torque.
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