Twin-Turbo V8 engine battle: BMW vs. Audi vs. Mercedes

Engines | July 13th, 2015 by 15
2014 BMW M6 Gran Coupe engine 2 750x500

All of the German big three, Audi, BMW and Mercedes-Benz, each have their own big twin-turbo V8 that they pump out in a variety of …

All of the German big three, Audi, BMW and Mercedes-Benz, each have their own big twin-turbo V8 that they pump out in a variety of different high-performance cars. Each company’s has unique attributes that make theirs special, but they’re all pretty great engines that make a lot of power. So let’s take a look at how they stack up against each other.

The kind folks at BoostAddict have gathered some data and made some nice charts to demonstrate the differences of each engine.

Audi 4.0 liter TFSI Twin-Turbo V8

2014 audi rs7 engine 1050x697 750x498

Audi has, in recent years, been using a 4.0 liter TFSI twin-turbo V8 in cars like the S6/RS6, S7/RS7 and the S8. This engine has proved very powerful , very smooth and highly efficient, being one of the better high-performance V8’s on the market. It uses twin-scroll turbochargers on all RS models, while the standard S models get single-scroll turbos.

audi 4.0 tfsi 375x500

The 4.0 TFSI features two top-mounted turbochargers, mounted inside of the vee of the engine, variable valve timing and direct injection. It’s a highly sophisticated engine that, despite being the smallest of them all, develops just as much power as the bigger engines in its class. The 4.0 TFSI, in RS7 guise, produces a peak 560 hp around 6,600 rpm and 516 lb-ft of torque at around 5,500 rpm, though the majority of the torque comes in at a tick over 2,000 rpm.

BMW S63TU Twin-Turbo V8


BMWs famous S63TU engine, the 4.4 liter twin-turbo V8 that BMW has used in nearly all of its big performance cars for years now, is a serious contender. The S63 also has top-mounted twin-scroll turbocharger mounted in the vee of the engine and also features variable valve timing and direct injection.


The BMW and Audi engines are remarkably similar, in terms of design and power. In M5 guise, the S63 produces 547 peak hp at a touch over 6,000 rpm and its torque peaks at 504 lb-ft very early at just under 2,000 rpm. So the BMW makes more horsepower but less torque than the Audi 4.0 TFSI, though its peak torque does come in a bit sooner.

Mercedes M157 Twin-Turbo V8


The Mercedes-Benz M157 is getting a bit old, but is still being used in most of Mercedes’ bigger AMG models. The M157 is a 5.5 liter twin-turbo V8, though it doesn’t have its turbos mounted in the vee nor does it have twin-scroll turbos. So it’s a bit old school, especially considering it having the biggest displacement of the bunch. This gives the E63 AMG a more linear powerband, with torque and horsepower seemingly coming in smoother, though it does develop a lot less power and falls flat at its 6,250 rpm redline, while the Audi and BMW keep on going a bit longer.


One of the Merc’s M157 variants makes 557 hp at around 5,500 rpm and peak torque of 531 lb-ft comes in at around 3,000 rpm. Admittedly, Mercedes has developed a 4.0 liter twin-turbo V8 with all of the same new-age tech that the Audi and BMW have, but at the moment is in smaller cars and makes less horsepower, like the C63 AMG.

So while Audi and BMW are almost neck and neck with their two big V8’s, Mercedes seems to be lagging behind a bit. The BMW might be a bit more powerful, but the Audi’s got more torque and it comes in a bit sooner, while the Benz is a distant third in terms of both. The one advantage the Merc might have is the noise, however, as the M157 sounds excellent. Not that the other two don’t, but the big Benz’s all sound just a bit better.

All three are excellent engines, develop an incredible amount of power and are all incredibly smooth. If I’d have to give a victory to just one, though, it’s have to be the Audi 4.0 TFSI over the BMW S63TU by the slightest of margins. The only things to give the Audi 4.0 TFSI the win are its smaller, more compact size and slightly better fuel economy. Other than that, these two are the best big German engines you can currently buy.

15 responses to “Twin-Turbo V8 engine battle: BMW vs. Audi vs. Mercedes”

  1. Audi > alle eure Mütter says:

    Rofl this ‘article’ ist just riddled with factual errors. I mean seriously are you just incapable of doing any research at all?

    • Horatiu B. says:

      What are the errors?

      • Audi > alle eure Mütter says:

        All the engine specs are just wrong. The Audi v8 does not produce 32 hp ‘around’ 6000 rpm. The m157 does not produce 458 hp. Torque figures are wrong as well. But i’m not doing his fact checking so he should look it up himself. Also there are different versions available of all three engines so the comparisons are wrong as well.

        • Horatiu B. says:

          The 32hp was a typo, fixed that to 560 hp. Torque was 516 even though some sites list it at 511.

          • Audi > alle eure Mütter says:

            But it’s available from 1750 – 5000 rpm. So that’s wrong. S63 hp, rpm are wrong. M157 hp, torque and rpm are wrong. S63 is available with 600 metric hp. M157 is available with 585 metric hp. M157 also produces most torque of the three. So his comparison and conclusion are wrong. And so on.

  2. Dan_d says:

    And what about Mercedes 4.0 V8 from AMG GT? Why is it not relevant to this comparison?

  3. Frankie G says:

    Sorry Horatiu but the others are right. BMW’s S63 produces 600 metric hp and 516lb ft in its most potent form (M5 30 Jahre Edition) and Benz’s 5.5 produces 585 metric hp and 590lb ft in most AMG ‘S’ variants. Not sure why you of all people got those numbers wrong..?

  4. John Vicic says:

    Suggest you do homework on your specs and conclusions. M157 was dynoed over 550 hp at the wheels by Motortrend (see youtube) more than S63TU competition. The E63s consistently beats M5 and matches with Audi. And engine is not old . You dont seem to understand how hp and torque come in versus displacement

    • paddy says:

      John vicic your also wrong. since when has the c63 or rs6 ever won an m5? you get ye facts rights. auDi are the worst out the German bunch.. poorly built slow unreliable pieces of crap

  5. Redeemed says:

    All these experts …be still my gut!

  6. Fat Clemenza says:

    Hello, does anyone here have thoughts on these two articles (below) about BMW turbo-4.4 failures? Not asking to be a smart-ass; would like to buy a used 650i Cabrio but scared off by these articles & by other research indicating BMW repair costs are 50% higher than Benz & Audi. I’ve driven Audi’s for the last 15 years and did not think higher costs were possible! I’ll post this question elsewhere on the blog too. Thanks!

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