Audi Makes a Bold Return to Diesel With Its Next-Gen V6 TDI

Audi has just unveiled something most of us never expected to return: a brand-new diesel engine destined for the Q5 crossover. This latest-generation oil burner features a 48-volt mild-hybrid system and an electrically driven turbocharger, technologies designed to reduce emissions, increase power, cut turbo lag, and ensure compliance with today’s stringent standards. And importantly, it does all of this without the shortcomings that contributed to the brand’s infamous diesel troubles a decade ago.

Looks Like Torque’s Back on the Menu, Boys

You can hardly blame us for assuming diesel engines—at least in passenger cars—were on their way out. A decade ago, compression-ignition powerplants accounted for roughly half of all new vehicle sales in the EU. By last year, that number had dropped to just 13.6%. Many automakers even argued that upcoming Euro 7 emissions regulations would render new diesel development impractical.

Audi itself had intended to end development of new combustion engines by next year and discontinue them entirely by 2033. That plan, unsurprisingly, has shifted—so here comes the brand’s newest addition: a 3.0-liter V6 TDI.

The engine itself—now in its fourth iteration of the EA897 family—remains largely unchanged. The real improvements come from the new supporting hardware that boosts both efficiency and economy. Leading the upgrades is a redesigned electric compressor. Audi has experimented with electric turbocharging before, but never at this level.

Thanks to its integration with Audi’s latest mild-hybrid setup and 48-volt electrical system—and a significantly more powerful electric motor—the new compressor delivers stronger output and builds boost far more quickly. Working in tandem with the 48-volt belt-driven starter-alternator, which can spin up the engine rapidly, and the electric motor within the gearbox, the system helps the V6 reach operating speed faster and provide near-instant boost. Audi says the result is “substantially improved” acceleration in the first 2.5 seconds after you pin the throttle.

Better Response, Better Economy—Now Bring It Here

Even better, the added low-end torque means there’s no need to rev the engine hard. That alone trims fuel consumption further, and Audi says the improvement is “significant.” The Q5 hasn’t offered a V6 diesel in several years, but the new version is projected to return 35–41 mpg combined on the WLTP cycle. In the A6, efficiency climbs even higher, with estimates of 39–45 mpg.

The previous 3.0 TDI offered in the Q5 was the Evo 2 version, producing 286 horsepower and 457 lb-ft of torque. The new engine bumps output to 295 horsepower and 428 lb-ft. Yes, that’s a slight drop in torque—until you factor in the 24 horsepower and 170 lb-ft contributed by the electric motor ahead of the transmission, which pushes the system’s peak output well beyond the old setup.

For one final eco-friendly flourish, the new TDI is capable of running on vegetable-based fuel. It’s certified for HVO—hydrotreated vegetable oil—produced from waste sources such as used cooking oil and agricultural byproducts. HVO can be mixed with conventional diesel or used entirely on its own. In fact, vehicles built in Ingolstadt and Neckarsulm will leave the factory filled with HVO, which Audi says can cut CO₂ emissions by up to 95 percent compared with standard petroleum diesel.

But before you start hoping to spot one at your local Audi showroom in the U.S., don’t. The odds of this drivetrain making it stateside are essentially zero. The wounds of Dieselgate are still fresh, and hybrids have long since taken over the space diesel once occupied in the American mainstream market.