For all the engines Munich has produced—from the screaming S14 of the E30 M3 to the torquey brute force of the S85 V10—none match the mythos, engineering purity, or historic importance of the one developed for a car that doesn’t even wear a roundel: the V12 at the heart of the McLaren F1.
Yes, the greatest BMW engine ever made may very well be the one designed not for a 5 Series or M car, but for a low-volume British hypercar that redefined what performance could be in the 1990s. The F1’s engine wasn’t just a masterpiece—it was the soul of a car that many still consider the greatest road car of all time. And that’s not a coincidence.
The Origin Story
The McLaren F1 project began with an uncompromising vision from Gordon Murray: a lightweight, central-seat road car with Formula 1 levels of engineering purity. But when it came time to choose an engine, no one could meet the brief. Honda said no. So did every other major player. It was BMW Motorsport—specifically Paul Rosche, the legendary engineer behind the M88 and countless other masterpieces—who stepped up and said, “Yes. But only if we can do it right.”
The result was engine code S70/2. A naturally aspirated 6.1-liter V12 producing 618 hp and 479 lb-ft of torque—numbers that still raise eyebrows today. But it wasn’t just about peak output. The engine was a technical flex, a study in balance, response, and durability. It could idle like a luxury sedan but screamed to a redline just north of 7,500 rpm with a sound that belongs in a museum. It was over-engineered in the best way possible—so much so that it ran dry-sump and had dual ECUs managing twelve individual throttle bodies. Murray had wanted a lightweight, high-revving motor with instant response and no forced induction. BMW gave him exactly that.
Built Different
We throw around the term “race engine for the road” far too often. But the S70/2 was exactly that—born from motorsport know-how and tailored with the restraint of real-world usability. It was lighter than most V8s of its day, yet had more cylinders and more sophistication. And its cooling system was so effective that even when raced at Le Mans, it needed no mechanical changes beyond standard endurance prep.
This wasn’t a development of the production S70B56 found in the 850CSi. It shared a name—and not much else. The McLaren’s V12 was a bespoke creation. Cosmetically, it looked beautiful. Functionally, it was overkill in the best way possible. And unlike most of BMW’s M engines, the S70/2 was never softened, detuned, or massaged to fit a broader product lineup. It existed for one car, and one purpose.
BMW S70/2 vs. S70B56: A Tale of Two V12s
It all begs the question, what does it share with other BMW V12’s of the time period. Of all production V12, it’s the E31 850csi’s S70B56 that comes the closest. But the moment you look at the data, you really begin to see the differences. From the number of valves to the 12 individual throttle bodies, there’s clearly a different intent and level of sophistication between the two.
| Feature | S70/2 – McLaren F1 | S70B56 – BMW 850CSi |
|---|---|---|
| Displacement | 6.1L (6064 cc) | 5.6L (5576 cc) |
| Layout | 60° V12, DOHC, 48 valves | 60° V12, SOHC, 24 valves |
| Power Output | 618 hp @ 7400 rpm | 375 hp @ 5300 rpm |
| Torque | 479 lb-ft @ 5600 rpm | 406 lb-ft @ 4000 rpm |
| Throttle Bodies | 12 individual | Single throttle body |
| ECU | Dual ECUs (TAG Electronics) | Bosch Motronic 1.7 |
| Redline | ~7500 rpm | ~6000 rpm |
| Induction | Naturally aspirated | Naturally aspirated |
| Fuel System | Sequential injection | Conventional injection |
| Dry Sump | Yes | No |
| Production Intent | One-off, motorsport-derived | Road car refinement |
| Weight | ~265 kg (584 lbs) | ~240 kg (530 lbs) |
How Does the S70/2 Compare to the Prototype E31 M8?
Things get more interesting when we look at the stillborn E31 M8 prototype and it’s V12 – code-named the S70/1. Interestingly the McLaren F1’s engine was derived from the BMW M8 prototype’s engine design – which was on the drawing board before McLaren approached BMW. They’re identical in terms of overall design concept and even size. The S70/1 even produced around 550 horsepower, close the 627 hp from the F1. However BMW has always been clear to point out that the S70/1 served as the foundation that the S70/2 was born from.
The Legacy
There’s a reason the McLaren F1 still holds the title for the fastest naturally aspirated car ever built. In 1998, it hit 240.1 mph with the rev limiter removed—more than two decades before Ferrari, Porsche or even Bugatti caught up. And at the center of that record? A BMW-built V12.
The engine’s influence didn’t directly echo through BMW’s mainstream lineup—but it didn’t need to. Its legacy is in its singularity. It was an uncompromised engine built for a car with no peers. No other production BMW motor can claim the same level of bespoke craftsmanship, historical impact, and mechanical perfection.
Why It Still Matters
In a world shifting rapidly toward electrification and turbocharged everything, the McLaren F1’s BMW V12 feels like a postcard from another era—a reminder of what engineering passion and corporate bravery can produce. It’s a monument to BMW’s motorsport division at its absolute peak, when “The Ultimate Driving Machine” wasn’t just a tagline—it was an ethos. But interesting, it also seems to be a blueprint for the future. With Murry Automotive, Bugatti, and Aston Martin all releasing high-revving naturally aspirated engines recently, it would seem that there’s some magic left in BMW’s formula.
So, is the McLaren F1’s S70/2 the best BMW engine of all time?
Without question. Not just because it sits at the heart of arguably the best analogue car of all time and even went on to win LeMans twice. It’s because it captures everything BMW M has stood for since its inception.
