Ferdinand Piëch’s one-off BMW M5 W10 goes under the hammer in Belgium on October 9, 2026. Under its hood sits a 5.0-liter Volkswagen W10 engine rated at 473 horsepower. Because only three of those engines were ever built, this lot is unusual: it includes two of them.
From the outside, the car looks like an ordinary black E39 M5. However, it was a Volkswagen engineering test bed, and Piëch used it as his personal car during testing, Broad Arrow says. Now Broad Arrow will offer it at its Zoute Concours Auction with an estimate of €250,000 to €350,000.
Here is what the auction house and the outlets that have examined the car say about how it came to exist, what the W10 engine is, and why it never went any further.
Why Piëch built a BMW M5 W10
Broad Arrow sets the scene in its September 24, 2026 release. “At the turn of the Millennium, BMW ruled the performance sedan class with its mighty E39 M5,” it says, “and Piëch decided to explore a Volkswagen rival.”
BMWBlog reports that Piëch told his engineers in 1999 to build a W10 for a high-performance sedan. According to that outlet, the program ran outside Volkswagen’s official research and development department. Autoevolution adds that engineer Sabine Willeke led the work, and that Piëch drove the car on temporary plates.
Rather than build a new body, the team used a BMW. Before the swap, autoevolution reports, this particular M5 left the factory in March 1999 as a 2000 model. In other words, Piëch tested his engine idea inside the very car he wanted to beat.
What the W10 engine is
At heart, the W10 grew out of Volkswagen’s narrow-angle VR6. According to Broad Arrow, Piëch expanded that VR concept into the W10, “a 5.0-litre powerhouse delivering 473 horsepower and 592 Nm of torque.” In U.S. terms, that torque figure equals about 437 lb-ft, the number BMWBlog and moto+match both quote.
Autoevolution describes the layout as ten cylinders arranged in a W that share a single crankshaft. It also gives the European rating as 480 PS. Meanwhile, BMWBlog describes the engine as all-aluminum and naturally aspirated, and it reports that the car uses a six-speed manual gearbox.
As a result, the output beat BMW’s own number. Broad Arrow says the W10 makes 79 horsepower more than a factory M5. For comparison, the stock E39 M5 used a 4.9-liter S62 V8, and BMWBlog’s figures put that engine at 394 horsepower.
Three engines and a shelved project
Even so, the W10 never reached production. Broad Arrow writes that it is “believed the costs of the project reached €2.000.000 before it was shelved.” That figure comes from the auction house, so it is an estimate rather than an audited number.
According to the release, “only three W10 engines were ever created.” One remains in Germany. Meanwhile, the second sits under the hood of this M5. Finally, the third comes with the lot as a standalone engine, which autoevolution says is mounted on a display stand.
BMWBlog reports that no other W10 went into a road car. It also says Volkswagen never returned to the ten-cylinder W layout after the program ended. Even so, autoevolution calls the W10 a missing link in the group’s W-engine story. Specifically, that story ran from a W8 in the Passat and several W12s to the 8.0-liter quad-turbo W16 used by Bugatti.
The BMW M5 W10 lot today
The car wears Carbon Black Metallic paint over a black leather interior, according to Broad Arrow. The September 27, 2026 report at gaycarboys repeats the same color, engine figures and estimate. Broad Arrow lists the lot as the “2000 BMW M5 Volkswagen W10 Prototype ex-Ferdinand Piëch.”
For buyers, that means a running prototype plus a spare engine of a type that exists only three times over. In fact, Broad Arrow’s Philip Kantor framed the whole sale around history. “Collector cars come in all shapes and sizes and from all eras,” he said in the release, adding that provenance strongly lifts desirability at auction.
When and where it sells
The live Zoute Concours Auction takes place Friday, October 9, 2026, at Approach Golf in Knokke-Heist, Belgium. Broad Arrow holds it during Zoute Grand Prix Car Week, and it is the company’s second annual sale there. Also, a separate online auction, Global Icons: Zoute Online, runs from October 5 to 14.
No result exists yet, because the sale has not happened. For now, the record shows a 2000 BMW M5 carrying one of three Volkswagen W10 engines, rated at 473 horsepower and 592 Nm, with a second W10 in the same lot and an estimate of €250,000 to €350,000.
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This article was created with the help of AI and was reviewed and edited by Fast Lane Only editors before publication.
