Road Test – BMW X5 Diesel

Diesel without the Sacrifice

Story and photos by Budd Stanley, additional photos courtesy of BMW

Late November 2007, I found myself lapping BMW’s Performance Driving Centre in the driving rain behind the wheel of the all-new BMW X5. With one of the head engineers guiding me around the track, he claimed to me that this new “SAV” or Sports Activity Vehicle as BMW insisted on calling it, could handle a corner as well as its 3-Series sibling. After about ten laps, I believed him, with the aid of the direct-injected 4.8L V8 heaving the 2,380 kg SAV out of the corner with the utmost of ferocity. As a performance car enthusiast, I’ve never really been a big fan of this segment of vehicle, but the new X5 gave a good smack in the face that told me a versatile vehicle can also be fun to drive.

It was at this global launch that BMW teased us with the diesel version as the European media were also in attendance. While the gasoline powered X5s impressed, the diesel-powered version had me quite intrigued, although at the time, there were no plans to bring the diesel to North America. The truth of the matter is that North Americans (mostly Americans) just don’t like diesel vehicles, unless it’s a work truck. Well, a lot has changed in the last couple of years. Fuel prices, along with environmental and economic concerns, mean that people are now looking to spend their money in a much smarter way. And thus the market is beginning to look at diesel in a whole new way.

And so we have it, the X5 diesel is here, now named the BMW X5 xDrive35d. Yup, it’s a mouthful. This new line in the X5 breed features BMW’s award-winning 3.0L turbocharged straight-six with the new BluePerformance Advanced Diesel technology. So, what is BluePerformance, and what does it mean to you? Well, this technology will likely make you think diesel rather than buying a smaller gasoline powered car.

BluePerformance is BMW’s achievement from the Bluetec development project. This was the research into making diesel technology cleaner and more socially acceptable. In other words, you get a diesel-powered vehicle with excellent mileage and huge power, without the noise, smoke or smell of a conventional diesel-powered vehicle. This is done by utilizing direct injection from its common rail-type fuel system that contains fuel pressurized to 1,600 bar or 26,000 psi. Two turbochargers, mounted sequentially, keep turbo lag at a minimum, while providing effortless power throughout the rev range, and giving the mid-size vehicle 265 horsepower and a massive 425 pounds-feet of torque to complete the performance side of the equation.

On the environmental side, the diesel’s exhaust uses urea injection to lower NOX emissions. After being injected into the exhaust gases, the urea solution creates ammonia that then converts the nitric oxides (NOX) in the exhaust into environmentally friendly nitrogen and water vapour. Like similar systems, the urea supply must be refilled occasionally; however, by equipping the X5d with 23 litres of urea capacity in a pair of tanks, one of which is heated to ensure a fluid urea solution in temperatures below -11 degrees Celsius, BMW has managed to fit the urea refilling periods within the standard scheduled maintenance stops, and will cover the cost of the refills and solution for the first four years or 80,000 kilometers.

So this technical talk is all well and good, but does it make diesel a more seductive fuel alternative? In a word, yes! The result is that you have a vehicle with all the versatility of an SUV, the class and handling of a performance luxury sedan, the power of a large V8 matched with the economy of a small V6 sedan. I don’t know about you, but that sounds like a winning combination to me. And that’s exactly how it feels on the road.

The sheer amount of low-end torque means both nipping around town and passing on the highway are near effortless and more civilized acts. A gasoline-powered vehicle requires downshifts to put it in the needed power band, and the engine revs hard to pull you past slower traffic. With the diesel, you only have to press the throttle, and allow the mountain of torque to thrust you forward. When matched to the xDrive AWD drivetrain, the usefulness of all this lowdown torque made the X5 surprisingly competent off the beaten path. The xDrive system includes a centre diff with a collection of clutch packs to provide torque to either front or rear axles, with a static distribution of 60 percent rear, 40 percent front, and the capacity to send full power to either end. With the DSC on, traction was maximized, and the lack of wheelspin got the BMW up a steep and slippery grade with ease. Conversely, with the DSC off, the diesel’s low-range torque and excellent six-speed automatic transmission kept the wheels spinning to power out of sticky situations. For a full report on how the X5 compared to its luxury SUV competition in off-road conditions, be sure to check out the Spring issue of Trucks Plus Magazine.

The only downside that I personally found with the diesel, was that it wasn’t gasoline. I love a great sounding engine, and the BMW gasoline straight-six does play a magical tune. Also, I love shifting gears and playing in the rev band, and you really just don’t need to with this vehicle. So, the diesel is almost too efficient for me, as high revving and gearshifts are simply not needed. For the average consumer looking at getting into an X5, this will likely not be a problem, and to be honest, it is something I could easily live with.

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