Road Test Comparison: 2007 BMW X5 and 2007 Land Rover Discovery 3

Although the opportunity to test at less than 20 degrees F didn't happen the X5 always started immediately, and it warmed to the point of supplying occupant heat noticeably faster than the iron-block TDV6. Despite its inline layout, it sounded similar outside, while inside it made a deeper thrumming sound than a BMW gas six. The BMW did, however, have a much more detectable turbo whistle.

With nearly the same ponies, a chunk more torque, and the same gearbox ratios, the X5 diesel feels faster than it is. You need to load the converter to make it snap your neck, and you get the impression that if the gearbox shifted faster it would significantly cut performance times. However, that same torque might render the gearbox recycling material, so the X5 goes near the 4600-rpm mark where the "yellow" line starts at wide-open shifts, falls off boost, and ramps it back as soon as the next gear's locked in. The sport mode feels more aggressive than in the TDV6, even factoring in the X5's added power and lighter weight.

An X5 diesel could go anywhere it needed to keep up with traffic, never reaching past 2200 rpm until exceeding U.S. speeds. It's no high-performance car (if BMW installs the two-stage turbo 3.0-liter, at about 270 horsepower/420 pound-feet, you'll never want a V-8), but it rarely needed a downshift to return to its chosen maximum speed. And at well past 25 mpg in everyday use, it might better a CRD and make an SUV hybrid seem rather boring.

Without import plans, prices are conjecture at best. In Land Rover's home market (England), an X5 3.0-liter diesel starts at about $700 more than the 3.0-liter gas engine, but that doesn't account for currency fluctuations and taxation clauses. Were they to make it to the U.S. we'd expect an LR3 diesel to be contented like the gas V-6 and priced just below a V-8 HSE, and the X5 to come in a bit below a 4.4i. We can only hope.