2023 Audi S6 TDI — 0-62 mph in 5 seconds, 155 mph
A prime example of the advancements in diesel technology is the fact that Audi moved its sporty S6 executive sedan/wagon to a turbodiesel engine in 2019. It was a bold move, but one that brought impressive efficiency to a passenger car that could compete with supercars of yore. Namely, the S6 TDI is good for 36.2 mpg combined, an impressive feat for an engine that needs only 5 seconds to reach 62 mph. Not only that, but it also has an astronomical range of 620 miles on one tank.
The key positive of the changeover is that the 3.0-liter V6 unit suits the S6 probably better than the previous gas model. See, the S6 has never been about agility and precision; instead, most of its owners used it to eat miles at high velocities. A turbodiesel engine is perfect for that type of driving, particularly one with 339 hp and 516 lb-ft of torque.
Still, Audi did everything it could to improve responsiveness; for instance, the mild-hybrid system powers an electrically-assisted compressor that eliminates turbo lag. Optionally, buyers can also get four-wheel-steering, which improves the handling and makes the S6 TDI quite sporty to drive. Add to that a smooth-shifting eight-speed automatic, and you have one of the most effortless fast executive cars on the market. Well, at least Europeans do — the excellent North American Audi S6 we drove last year still packs a gas-powered twin-turbo V6.
2024 Audi S4 TDI — 0-62 mph in 4.8 seconds, 155 mph
The S4 TDI shows that weight is key when it comes to performance, as it packs the same mild-hybrid 3.0-liter TDI from the S6 and is 0.2 seconds quicker to 62 mph. Okay, this version has 341 hp, but the torque is the same. Besides, in this case, the S4 is closer in terms of power to the North American version, which has 349 hp and 369 lb-ft and hits 60 mph in 4.4 seconds (0-62 mph time would be much closer).
But thanks to the much greater torque, the diesel-powered S4 would be a great long-distance cruiser despite having a slow initial response. Overtaking with that much torque is a breeze, even if you leave the eight-speed automatic in the highest gear on the highway. Moreover, it gets an excellent fuel economy of 40.9 mpg combined with Europe’s new WLTP standard — over 10 mpg more!
Of course, the S4 TDI won’t be as fun to drive as a gas-powered sports sedan or wagon (yup, there is an Avant version). But for most people, the combination of Quattro AWD and good body control is enough to put a smile on their faces. This is a car that will get you anywhere quickly without too much drama. A true 21st century highway express.
2024 BMW M340d xDrive — 0-62 mph in 4.8 seconds, 155 mph
BMW
BMW also has an M Performance model with a diesel engine. It’s not a true M car, yes, but it can still rip asphalt with ease. Under the bonnet, it packs a mild-hybrid, twin-turbocharged 3.0-liter inline-6 producing 340 hp and 516 lb-ft of torque, giving it similar acceleration to the V8-powered E92 M3. Impressed? Wait until you hear that it can go 700 miles on one tank and achieve a realistic 35 mpg. It really makes you wonder why we are not driving more diesel-powered cars.
But again, that torque steals the show here. The mid-rpm punch of the M340d xDrive is second to none, giving you the feeling of a much more powerful engine. In BMW’s case, the turbodiesel also has a decent sound, producing quite a sporty noise. Like most BMWs of late, the M340d xDrive is devoid of feel. Still, it’s not like the competition is better in that regard. The 3-Series remains the handling benchmark, so it’s overall a more dynamic vehicle than the S4.
BMW managed to combine excellent agility with a smooth and quiet ride, making it an excellent long-distance cruiser. Insides, you also get all the latest BMW goodies, like the well-made and tech-laden interior with one of the best infotainment systems in the business.
2024 Mercedes-Benz E450d 4Matic — 0-62 mph in 4.8 seconds, 155 mph
Mercedes-Benz
Predictably, Mercedes-Benz wouldn’t just stand on the sidelines and watch Audi and BMW exchanging torquey diesel blows. So, the Stuttgart-based manufacturer equipped the latest E-Class executive saloon/wagon with a 3.0-liter inline-6 turbodiesel, aided by a mild-hybrid setup that gives an additional 22 hp of boost. The end result was 390 hp and Earth-spinning 554 lb-ft of torque, channeled to all four wheels via a nine-speed automatic transmission.
Unlike the previous entries on this list, though, the E450d 4Matic isn’t particularly interested in carving corners like a sports car. You can get the E450d 4Matic with four-wheel-steering, which aids with agility but still doesn’t do much in making it a fun-to-drive vehicle. Quite the opposite, in fact, as Mercedes-Benz doubled down on comfort with the latest E-Class. Equipped with air suspension, the Merc’s latest executive car glides over the road and remains silent on the highway.
It achieves high velocities effortlessly, too, thanks to the significant torque available at low rpm. The numbers say that it is on par with the gas-powered 375-hp E450 4Matic we tested earlier this year, which hits 60 mph in 4.4 seconds, though the turbodiesel should feel punchier at speed. Still, there is a lot of distracting tech inside the new E-Class, like a selfie camera that you can use for video conferencing or even TikTok — not a smart move in such a powerful vehicle.
2017 Audi A8 4.2 TDI Quattro — 0-62 mph in 4.7 seconds, 155 mph
Audi
Before Audi switched the A8 to an all-gas affair in 2018, the company offered its luxury limo with a 4.2-liter V8 twin-turbo diesel engine. Packing 385 hp and truck beating 627 lb-ft of torque, the most powerful diesel A8 ever provides supercar-rivalling performance while delivering outstanding 32.6 mpg. For reference, the latest F-150 Hybrid only has 570 lb-ft of torque. That’s diesel power, in a nutshell. However, the most impressive part is the power delivery. Because of the larger capacity, the V8 TDI pulls from very low rpm, achieving full torque at 2,000 rpm.
This torquey turbodiesel engine seems like a perfect fit for a luxury limo. It’s quiet, unlike the diesels of yore, and works together with the slick-shifting eight-speed automatic to provide a stress-free driving experience. Meanwhile, the Quattro AWD system ensures that the tires always have good traction, even when you accelerate hard, resulting in a 0-60 mph time of only 4.5 seconds — all in a huge German sedan that can go 667 miles on one tank. Too bad Audi limited the top speed to 155 mph.
2022 Bentley Bentayga Diesel — 0-62 mph in 4.8 seconds, 168 mph
Bentley
Bentley is one of the most unique companies in the automotive industry. Its cars have always had two distinct personalities — a hyper-luxurious, Rolls-Royce-rivaling one and a speedy one. The idea: To reach your destination faster, without sacrificing comfort and luxury. And the now-discontinued Bentayga Diesel is probably the ultimate version of that recipe.
The car’s tour-de-force 4.0-liter V8 turbodiesel engine has an electric compressor that spools up from low rpm to delete lag, accompanied by one smaller turbocharger that delivers torque up to 2,200 rpm, then slowly merges with a larger turbocharger, which takes over at 2,700 rpm. So, yeah, reliability could be a huge issue. Still, the technology allows this diesel unit to achieve a whopping 664 lb-ft of torque, available at jaw-dropping 1,000 rpm and then up to 3,200 rpm! The 429-hp figure certainly seems tame by comparison.
As you can imagine, driving a Bentayga Diesel is as effortless as it gets — you basically have EV-like torque. There is also almost no accompanying noise: The Bentayga’s Audi-sourced diesel is super-quiet and refined. Add to that a possible 620-mile range, super-comfortable and lavish cabin, and a higher 168-mph top speed, and it becomes clear that the Bentayga Diesel is one of the best long-distance cruisers the industry has ever seen.
2019 BMW M550d xDrive — 0-62 mph in 4.4 seconds, 155 mph
BMW
Four turbochargers. We are not talking about how many turbochargers a certain repair shop has in stock. It’s how many blowers are attached to BMW’s ridiculous B57S diesel engine. Sounds like a reliability nightmare, sure, but you have to give BMW props for making it work. Not only that, but this 3.0-liter inline-6 produces 400 hp, or 133.6 hp per liter, an outstanding number for a diesel. The torque it produces is equally impressive at 561 lb-ft, available at 2,000 rpm. And thanks to the quad-turbo setup, 330 lb-ft is available at 1,000 rpm!
BMW’s engineers used all sorts of trickery to get to those numbers. For instance, of the four turbochargers, two were smaller for that low-end grunt, while the two others were larger for more power at higher revolutions. One of the larger turbos lays dormant during regular driving — it’s only awakened when you push the pedal to the metal, making the M550d xDrive shoot forward like a catapult, and providing better performance than all but the last two BMW M5 generations. It would destroy them all on efficiency, though, with BMW claiming 45.5 mpg. Admittedly, that’s on the lenient European NEDC cycle, but it’s impressive nonetheless.
2020 Porsche Panamera 4S Diesel — 0-62 mph in 4.3 seconds, 177 mph
Porsche
Porsche and diesel don’t resonate on paper. Most Porsche enthusiasts would even call that combination a heresy. Nonetheless, the days of Porsche being a company that produces only air-cooled engines are way behind us. Today’s Porsche is all about competing in every sector and beating the competition. So, of course, Porsche’s fastest diesel car is also the fastest production diesel vehicle, period.
Packing a 4.0-liter bi-turbo V8, the same one found in the Bentley Bentayga Diesel and Audi SQ7, the Panamera 4S Diesel can achieve some world-beating numbers. With the Sport Chrono package, it reaches 62 mph in just 4.3 seconds (4.5 seconds without it) and won’t stop accelerating until the needle hits 177 mph. Brutal, yes, but also effortless. Namely, this svelte 422-hp four-door sports car/wagon has a massive 627 lb-ft of torque available from 1,000 to 3,200 rpm, so it will accelerate without hesitation in any gear. Put the eight-speed automatic in the highest gear on the highway, and it will still pull like its life depends on it.
Porsche doesn’t produce the Panamera 4S Diesel anymore — blame VW’s Dieselgate standard for that. But maybe such a powerful and efficient diesel combined with electricity makes sense? Even with a 48-volt system, it gets a spectacular 35 mpg combined. Electricity already did the latest 2025 Panamera E-Hybrid well, so we can only wonder how it would work with a potent diesel.
Audi R18 TDI e-tron quattro LMP1 Race Car — 215 mph
Now that we have given the Panamera 4S Diesel the title of the fastest-ever production diesel vehicle, it’s time to move to race cars. Yup, there were some very successful diesel racers in the World Endurance Championship (WEC), where the 24 Hours of Le Mans race is on the calendar each year. The combination of speed and efficiency made diesels almost unbeatable in the past two decades, and Audi had the most success.
Interestingly, Audi’s last entry at the 2016 Le Mans race, the R18 TDI e-tron quattro, was slightly slower than the brand’s previous entries. That’s because, for the 2011 R18 Ultra, Audi opted for a more compact 3.7-liter V6 turbodiesel (previously a V10), producing 532 hp and over 627 lb-ft of torque. The move was mainly because of the new regulations, but it also brought much higher efficiency and better packaging to the table.
Still, Audi was only warming up for the flywheel-hybrid e-tron quattro LMP1 entry, which featured an accumulator from Williams WHP and a motor generator unit from Bosch. Thus, the 2012 iteration of the hybrid R18 achieved 202.6 mph on the Mulsanne straight. Still, the last 2016 R18 racer, equipped with a battery-electric hybrid system and a larger 4.0-liter V6 engine, was the fastest one, achieving 214.75 mph. Despite that, it failed to win the race, finishing third behind the gas hybrids from Porsche and Toyota.
Audi R15 TDI Plus LMP1 Race Car — 216 mph
Audi’s second diesel entry at the 2009 Le Mans race was a real powerhouse, packing a 90-degree 5.5-liter V10 turbodiesel, producing over 600 hp and 860 lb-ft of torque. While it wasn’t enough — Peugeot won the race in 2009 — Audi introduced some new technologies that would soon be transferred into its road-going vehicles, like LED headlights and a lithium-ion battery instead of a lead-acid one. Moreover, the team won that year’s 12 Hours of Sebring race, showcasing the potential of the car.
However, winning Le Mans was always the main goal. So, Audi continued to push the engineering envelope the next year when it introduced the R15 TDI Plus, which had over 700 hp and a whopping 885 lb-ft of torque. The result of the power boost was a top speed of 216.24 mph at the Mulsanne straight and a one-two victory at the 2010 24 Hours of Le Mans. Regardless of that, the R15 TDI Plus was still slower than the Peugeot 908 HDI-FAP per lap, so Audi was back at the drawing board with the R18 TDI in 2011.
Peugeot 908 HDI-FAP LMP1 Race Car — 217 mph
Peugeot and its sister company Citroen’s HDi turbodiesel powertrains are very popular in Europe, offering excellent efficiency and good performance. In an effort to showcase its technology’s supremacy, particularly when compared to the German automakers, Peugeot entered the 2007 24 Hours of Le Mans race with a turbodiesel race car, the 908 HDI-FAP.
Like the Audi R10 TDI it tried to beat that year, the Peugeot LMP1 race car had a 5.5-liter twin-turbo V12, good for around 700 hp and over 885 lb-ft of torque. Interestingly, the cylinder banks were set at an unusual 100 degrees, for a lower center of gravity. Still, it was not enough for the 908 HDI-FAP to be the fastest LMP1 car that year, achieving 213.75 mph on the Mulsanne straight in qualifying, short of Audi R10 TDI’s 218.1 mph. Peugeot also finished second to the Audi.
However, the French company continued to improve the formula, and in 2008 achieved 217.5 mph in qualifying. It was still only good enough for second place, but it was evident that Peugeot was closing in on Audi. Finally in 2009, the French company won the Le Mans race, its third win at the Circuit de la Sarthe. The 908 HDI-FAP also topped at 213.1 mph during the race. Peugeot returned to Le Mans in 2023 with its radical 9X8 wingless hybrid racing car.
Audi R10 TDI LMP1 Race Car — 218 mph
Audi’s fastest diesel-powered race car was its first one. It’s not because the company couldn’t make the successors any faster — blame WEC regulation changes for that. However, top speed has never been the only factor in the 24 Hours of Le Mans race — reliability and luck are equally important. Still, there is no denying the success of the R10 TDI, which won in its first attempt in 2006, and repated the success in 2007 and 2008.
Unlike most modern LMP1 cars, the R10 TDI was an open cockpit design. Behind the driver, it packed a large 5.5-liter twin-turbo V12 diesel, producing over 700 hp and a massive 948 lb-ft of torque available from just 3,000 rpm. It was famous for its reliability, similar to Audi’s previous entry, the gas-powered R8, but the showstopper was certainly its capability in a straight line. The R10 TDI achieved 218.1 mph at the 2007 Le Mans race, making it the fastest-ever diesel car.
Some of that special V12 sauce could’ve reached public roads. Namely, Audi showcased the R8 V12 TDI concept at the 2008 Detroit Auto Show with a 6.0-liter bi-turbo V12 producing 493 hp and 738 lb-ft of torque. The world’s first diesel supercar even had a six-speed manual for more driving fun. Moreover, it could easily reach more than 186 mph and needed only 4.2 seconds to hit 62 mph. The R8 V12 TDI was drivable, but Audi never made a production model.
