Audi Introduces Its Latest V6 Diesel Engine Featuring Instant Turbo Response
As emissions regulations tighten across Europe, diesel engines are steadily losing ground. Their market share has dropped from over half before the Dieselgate scandal to a mere eight percent in the first ten months of this year. Diesel now ranks fourth in popularity behind hybrids, gasoline engines, and notably, plug-in hybrids, which have overtaken diesels for the first time.
Despite this decline, Audi remains committed to diesel technology. The brand has been producing diesel vehicles since 1989 and boasts eight Le Mans victories with TDI-powered race cars. Audi even developed a V-12 diesel engine for the R8 supercar, though it never made it to production. Now, looking ahead to 2025, Audi unveils a new 3.0-liter V6 diesel engine enhanced with electric assistance.
This advanced powertrain, debuting in the A6 and Q5 models, combines a mild-hybrid system with an electrically driven compressor. While Audi has previously offered 48-volt diesel setups, this is the first time the mild-hybrid system works alongside an electric compressor positioned in the intake pathway, behind the turbocharger and intercooler.
When accelerating quickly and the turbocharger lacks sufficient exhaust energy, the intake air is directed through the electric compressor. This component further compresses the air already pressurized by the turbo before it enters the combustion chamber, enhancing low-end torque and nearly eliminating turbo lag. Audi claims this setup provides throttle response comparable to that of an electric vehicle.
The engine produces 295 horsepower at 3,620 rpm and 428 lb-ft (580 Nm) of torque starting at 1,500 rpm. Compared to its predecessor, the peak boost pressure of 3.6 bar is achieved almost one second faster. The compressor wheel spins up to 90,000 rpm within 250 milliseconds, about 40% faster than before, delivering sharper off-the-line acceleration and allowing the car to cover roughly one car length more in the initial 2.5 seconds.
The mild-hybrid system adds a temporary boost of 24 hp and 170 lb-ft (230 Nm) when accelerating from a stop. On the road, the A6 Sedan equipped with this engine accelerates from 0 to 62 mph (100 km/h) in 5.2 seconds and reaches a top speed of 155 mph (250 km/h). The heavier wagon variant takes just 0.1 seconds longer.
Interestingly, the Q5 SUV, despite weighing the same as the A6 Sedan, accelerates even faster. Both the standard SUV and the Sportback version hit 62 mph in exactly five seconds, sharing the same electronically limited top speed as the sedan. Although the powertrain’s complexity might raise concerns about reliability, Audi assures that durability has been enhanced over the previous generation, alongside improved fuel efficiency.
A Closer Look at the EA897evo4 Diesel Engine
This isn’t an entirely new engine but rather the latest iteration of Volkswagen Group’s diesel engine introduced in 2010. Codenamed EA897evo4, this engine also powered select Porsche models before the brand abandoned diesel after the Dieselgate scandal. The EA897 was famously involved in the emissions cheating controversy.
Nevertheless, Audi asserts that this version is the cleanest in its history. It can run on hydrotreated vegetable oil (HVO), a sustainable fuel derived from waste cooking oils and agricultural residues, which can cut CO₂ emissions by up to 95% compared to regular diesel. Audi’s Neckarsulm and Ingolstadt factories in Germany have already begun fueling diesel vehicles with HVO.
While this engine is expected in upcoming Q7 and the larger Q9 SUVs, it’s unlikely to appear in the next-generation A7, which may not be produced, and the future of the A8 flagship remains uncertain.
