With every diesel SUV variant that I drive, I wonder why people are still buying the gas alternatives. Compared to its V-8 counterpart, this BMW X5 xDrive35d is just as comfortable, significantly more efficient, and less expensive. Rated at 19 mpg in the city, and 26 mpg on the highway, the X5 35d is also more fuel-efficient than the Mercedes-Benz GL350 BlueTec and the Audi Q7 TDI. As Phil mentions, the BMW diesel is a bit louder than both the Mercedes and the Audi, especially when cold or under acceleration. However, that's a negligible tradeoff for the excellent flexibility of this engine.
The 5000-rpm redline is great for hard acceleration, but what really impresses me is the on-tap power for moderate, in-gear acceleration. Where other vehicles are often calling for downshifts, the BMW is capable of giving a smooth, quick response just by adding more fuel. The rest of the driving experience is also very good. The ride is gentle without being soft, the transmission is rather transparent, and the steering is excellent, although quite heavy at low speeds.
Eric Tingwall, Associate Editor