Why Did So Many German Performance Cars Cap Their Top Speed At 155 MPH?
Why Did So Many German Performance Cars Cap Their Top Speed At 155 MPH?
Aakash BadreeSun, June 21, 2026 at 5:05 PM UTC
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red 2009 BMW M3 E92 on the road with trees in the background - Brandon Woyshnis/Getty Images
If you've spent any time around German performance cars from the past few decades, you've probably noticed most of them top out at 155 mph. That's not a coincidence. It's the product of an informal agreement between German automakers that has been shaping their cars for over four decades. The story begins in the 1970s with Germany's Green Party, whose advocates wanted to apply mandatory speed limits on the Autobahn.
Without a formal speed limit, drivers can reach insane speeds on the Autobahn today, but in the '70s, tire technology wasn't as advanced or capable of sustaining such high speeds. Politicians sought to impose speed limits while car manufacturers wanted to keep the Autobahn unrestricted. The solution Germany's automakers landed on was to regulate themselves instead. BMW, Mercedes-Benz, and Audi reached an informal agreement to electronically limit all their vehicles to 250 km/h, or exactly 155 mph. Porsche never joined the agreement.
It was a demonstration of industry responsibility, and it kept the government's hands off the Autobahn itself. By accepting a self-imposed ceiling, the manufacturers effectively argued that external speed limits were unnecessary. 155 mph was a fair benchmark as it's well within the limits of tire technology while still being an exhilarating speed that some may even say is too fast. And despite the top speed restriction, automakers continued to compete with acceleration times and technology features.
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How the 155-mph limit works in practice
An Estoril Blue F10 BMW M5, another victim of the 155 mph limit. - Dinkun Chen/Wikimedia Commons
The agreed 155 mph cap is achieved with an electronic limiter — not a mechanical one. The engines in most cars covered by the agreement are entirely capable of going faster. For example, BMW's F10 M5 could reach 190 mph without a limiter, but is lowered to 155 to adhere to the gentleman's agreement. To unleash the M5's full potential from the factory, buyers can choose the optional Driver's Package.
A similar Driver's Package exists for BMW's current M2, unlocking the sport coupe's true 177 mile-per-hour limit. That said, modern performance governors are not hard engineering boundaries. Tuners have long offered ECU remaps to remove the restriction for a few hundred bucks, and it's a simple modification for enthusiasts who want to get their money's worth for their more-than-capable performance cars.
Germany wasn't the only country where manufacturers agreed to limit themselves, either. In 1989, Japanese automakers reached their own gentlemen's agreement capping engine output at 276 horsepower. This agreement lasted roughly 15 years, but the underlying structure was the same: industry self-regulation to preempt government intervention. The 155-mph limit has also softened considerably over time. German manufacturers increasingly offer factory packages or features that raise or remove the restriction, and the performance arms of each brand routinely produce cars that operate at entirely different speed ceilings. What the agreement did accomplish, however, was keeping the Autobahn unrestricted to this day — which may have been the point all along.
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Source: “AOL Money”
