Monster diesel SUVs occupy a very small niche market, one so small, in fact, it makes cars like the BMW X6 M seem mainstream. However, despite their rarity, big performance diesel SUVs actually make a bit more sense than gasoline-powered performance SUVs. The BMW X5 M50D, a tri-turbocharged behemoth, is a perfect example. BMW had reigned king in the world of diesel performance SUVs for quite some time. But now, there seems to be a new competitor, the Audi SQ7 TDI.
Based on the second-generation Audi Q7, the SQ7 packs a triple-turbocharged 4.0 liter V8 diesel engine. However, it’s a bit more complicated than that. Two of the SQ7’s turbochargers are sequential, meaning one is used for low-rpm stuff and the other for high-rpm stuff. But the third is electrically-driven, and is much smaller than the other two, allowing it to add boost at nearly zero rpm, thus providing extra grunt low down while the smaller gas-driven turbo spools up. It’s the first production car to ever use an electrically-driven turbocharger, according to Audi. This tri-turbo setup allows for 435 hp and a whopping 663 lb-ft of torque.
By comparison, the BMW X5 M50D uses a 3.0 liter tri-turbocharged inline six-cylinder diesel engine, which develops 381 hp and 546 lb-ft of torque. So the BMW is down significantly on power, considering the smaller engine. It gets better fuel economy, though. The BMW X5 M50D can get from 0-60 mph in 5.3 seconds, while the SQ7 can do the same spring in 4.8 seconds. So the added power does help the Audi.
In terms of the way they drive, we’ve yet to sample either of them. We’ve driven the X5 M and it’s an outstanding car, so if that’s anything to go by then the SQ7 will have quite the uphill battle. However, having said that, we’ve also sampled the standard Audi Q7 3.0T and it’s a very good SUV with surprisingly sharp handling, excellent road manners and a very good chassis. So it’s possible that the Audi SQ7 brings some heat and really challenges the BMW X5 M50D.
In terms of looks, the X5 M50D is a very good looking car. The standard X5 is a stunner and, for me personally, is the more interesting looking car than the standard Audi Q7. I also think the SQ7 is also a very good looking car but, at least for me, lacks a bit of the visual drama and aggression that the M50D has.
On the inside, things are a bit different, as the M50D doesn’t look much different from the standard X5 with an M Sport package, which is a shame. It’s a very nice cabin, but doesn’t look any more special that the standard car, aside from those gorgeous leather/alcantara seats. On the flip-side, the Audi SQ7 looks very good on the inside, with a high-tech look and feel. It’s almost like sitting in the Starship Enterprise. However, it is a much newer cabin than the X5’s so it’s going to look fresher.
Both cars look really good, both have excellent interiors and both have stunning performance from triple-turbocharged diesel engines. So it will be very interesting to see which car is best.