First Audi SQ8 TDI revealed – tops S range with 429bhp V8 diesel

The Audi SQ8 TDI has officially been revealed, pairing the standard Q8’s sleek body with the V8 twin-turbo diesel found in the larger SQ7 TDI. Key figures are the same as for the SQ7, but the powertrain is now fully WLTP compliant, doing so without any compromise in power or torque.

As a refresher, the 4-litre twin-turbo V8 is bolstered by a 48V mild-hybrid system, which spins an electrically powered compressor (or EPC) to torque-fill at low revs before the two gas-driven turbochargers have a chance to spool. Those two turbochargers are sequential, with the smaller of the two taking over from the EPC first, while the second, larger unit gets into its stride at 2200rpm. Both turbos sit within the V8’s two cylinder banks, with the EPC unit housed behind the intercooler.

> Click here for our review of the Audi SQ7 TDI

The resulting outputs are still as impressive now as they were when the SQ7 was initially released in 2016, with a peak of 429bhp bolstered by a massive 664lb ft of torque available  between 1250 and 3250rpm. Power is transferred to all four wheels via an eight-speed automatic transmission. Audi’s torque vectoring Sport Differential is also available, which utilises a physical clutch pack on the rear axle to actively distribute the torque between the rear wheels.

The mild-hybrid system also powers Audi’s active anti-roll stabilisation system, which is designed to significantly reduce body lean under hard cornering while not compromising on straight-line ride comfort. The system works by activating two electric motors mounted on the centrepoint of each anti-roll bar. Under normal driving situations the roll bars remain decoupled, but under load, the electric motors twist the two anti-roll bars in opposite directions, in the process reducing roll. The system also recuperates kinetic energy and returns it to a small lithium-ion battery pack.

Four-wheel steering and an adaptive air-suspension system complete the technical upgrades, all of which are designed to make what is ostensibly an extremely large and heavy car feel smaller and more agile than it has any right to be.

The SQ8 TDI sits on standard 21-inch wheels, with 22s on the options list. Both will clear the also optional carbon-ceramic brake package, which might sound like a ridiculous addition until you remember the SQ8 TDI weighs in at way over the two-ton mark.

Aside from new wheels, badging and fresh colour and trim options, the SQ8’s design remains much the same as its more demure Q8 siblings. As the least coupe-like of its ‘coupe-SUV’ rivals, it remains one of the more attractive cars of its type, even if we’d generally take an RS6 Avant over one, every, single time. 

The SQ8 TDI will be available by the end of the summer priced from around £80k. If you’re after the most extreme of extreme Audi SUVs though, an RSQ8 is also on its way, with a possible hybridised twin-turbo V8 petrol powertrain packing over 700bhp. Suddenly 429bhp sounds rather meek.