It may have a diesel engine, but it sure doesn't sound like one.

With SQ2, RS Q3, SQ8 / RS Q8 in the works, it’s safe to say Audi is on the verge of expanding its portfolio of fast SUVs. Meanwhile, it’s slim pickings as there are only a handful of high-riding models from Ingolstadt built with performance in mind. One of them is the SQ7, a diesel monster with an intricate twin-turbodiesel 4.0-litre V8 engine churning a whopping 664 lb-ft of torque, much like the diesel-fueled Bentley Bentayga.

It’s no RS Q7 by any means, but it’s the next best thing by accelerating from a standstill to 62 mph in 4.8 seconds. That might not seem all that impressive compared to bona fide supercars, but let’s keep in mind the SQ7 is just about as heavy as a tank. Needless to say, we’re exaggerating to make a point, although at 2,270 kilograms without the driver, the performance SUV is not exactly a Mazda MX-5. Come to think of it, the SQ7 is more than two times heavier than the MX-5. Go for the seven-seat model and throw in some extras and the SQ7’s weight will increase even more.

See how it stacks up against entirely different cars:

Still, this video shows some impressive acceleration granted not just by the immense amount of torque, but also by the fact it kicks in extremely low in the rpm range, at just 1,000 rpm. An eight-speed Tiptronic has the difficult task to send the mountain-moving amount of torque to both axles, allowing the SQ7 reach 124 mph in about 18 seconds. Flat out, it will do an electronically capped 155 mph.

Thanks to an electrically powered compressor, the dreaded turbo lag is virtually nonexistent, while the two sequentially activated turbochargers give this Audi luxobarge amazing pulling power all the time. With this being a diesel, it obviously begins to show its limitations compared to a petrol unit once you reach higher speeds, but it’s still a monster of an engine. It doesn’t sound half bad either as the noise generated during hard acceleration is quite different than what you’ll hear in a multitude of TDI cars from the Volkswagen Group.

A forbidden fruit in the United States, the SQ7 is in high demand in Europe considering Audi’s website says the model is sold out for 2018MY.