Why you should care about Volkswagen’s 4.0-litre twin-turbo V8

Debate over the greatest V8 engines ever built is sure to prompt an impassioned response from any motoring enthusiast.

Any list of spectacular bent-eights will no doubt include the usual suspects of Ferrari’s free-breathing F136, Ford’s iconic modular family, Rolls-Royce and Bentley’s indomitable L Series, perhaps even Mercedes-AMG’s endearing M177/M178.

However, very few would take the time to single out the 4.0-litre TFSI twin-turbo V8 from Volkswagen Group. We think that needs to change.

Let us take this moment to sing the praises of modern motoring’s most underrated engine.

6

The mechanical construction of Volkswagen Group’s most powerful V8 is rather straightforward. Using 90mm bore spacing, the 4.0-litre unit is a modular version of the 3.0-litre V6 found elsewhere within the automotive giant’s family of luxury brands. Using a 90-degree vee angle, the 4.0-litre unit places a pair of twin-scroll turbochargers within the spread of its cylinder banks, with a bore x stroke of 84.5mm x 89.0mm.

The 4.0 TFSI unit can be found in a range of models, from Audi’s A8 saloon, to the previous generation S6/S7 twins and their RS counterparts, along with the RS Q8, plus Bentley Continental GT and Bentayga. Porsche use the bent-eight in its Panamera and Cayenne ranges, while the unit is at its most powerful when fitted to the Lamborghini Urus.

Lamborghini’s tune of the engine increases outputs to 478kW and 850Nm, with the V8’s most docile production guise being 309kW and 550Nm.

6

There is something capable but benign about VAG’s 4.0 TFSI unit – perhaps explaining its frequent omission from great V8 debates. It does everything you want of it on paper, with ample low-down torque, a satisfying exhaust burble, and plenty of top-end poke, but it never really stirs the soul.

Holding onto that narrow focus is a disservice to the versatile V8, which nails the brief for modern ICE engines. It can and has been fitted to a range of models, has a wide enough bandwidth of power to be used in for both high and limited production vehicles, and perhaps most importantly can sip fuel at a rate that appeases ever tightening emission regulations.

However, the 4.0 TFSI could soon go from flying under the radar, to dominating the world’s biggest endurance race.

6

Both Audi and Porsche are rumoured to be tweaking the engine for use in their LMDh prototype race cars.

While each manufacturer’s final choice for their LMDh cars is yet to be officially confirmed, in March last year Porsche Factory Motorsport Director Pascal Zurlinden told RACER “we have a portfolio for many engines on the road car side which could be an option.”

Adding: “the decision is done and it will be something great, I’m convinced of it.”

6

Porsche recently began testing its LMDh prototype, releasing footage that contains what sounds to our ears like a V8 engine note. Here’s hoping the 4.0 TFSI gets its moment in the sun.

So, to recap: the 4.0-litre TFSI has kept bent-eights firing across VAG’s family of brands where others are ditching cylinders with fervour, and is about to power Porsche and Audi’s return to top-flight competition at Le Mans. What more could be asked of an engine?

It’s time we all give the 4.0 TFSI V8 the respect it deserves.