I have never come across an analysis of the Mercedes CLR that flipped at Le Mans presented with such thorough detail.

      Mike Fernie via YouTube

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      The Mercedes-Benz CLR is remembered for all the wrong reasons. It notoriously took to the air, not just once but three times during the 1999 24 Hours of Le Mans, tumbling end over end and soaring over crash barriers as if it were created by a faulty video game physics engine. YouTuber Mike Fernie recently visited one of the surviving models, now part of the Loh Collection in Germany, and recounts its complete history in an in-depth video.

      The CLR was the outcome of an evolutionary process that started with the CLK GTR and CLK LM. These vehicles were designed to meet the GT1 regulations that governed the premier class of endurance racing in the late 1990s, primarily producing race cars that were dressed up as street cars. The CLR was constructed under LMGTP rules, shifting back toward specialized prototype race cars and permitting Mercedes to abandon the façade of a road car.

      Mercedes retained the CLK LM’s V8 engine but increased its displacement from 5.0 liters to 5.7 liters, encasing it in tighter bodywork. The well-known four round headlights and grille from the then-new C215 CL-Class coupe were positioned exceptionally low on the front, with the bodywork extending below the wheel arches. This design, featuring lengthy front and rear overhangs for large diffusers and a minimal rake, would ultimately lead to the CLR’s downfall.

      Mike Fernie via YouTube

      The V8 engine was loosely derived from the M119 road car engine, which, in its turbocharged version, had helped the Sauber-Mercedes C9 achieve victory at Le Mans a decade prior. In the CLR, it produced around 600 horsepower, effectively turning the car into an aircraft.

      Despite Mercedes claiming to have performed over 20,000 miles of testing, the three cars entered at Le Mans struggled on the high-speed straights of the Circuit de la Sarthe. Future F1 driver Mark Webber experienced takeoffs during both qualifying and a pre-race warmup. In his autobiography Aussie Grit, Webber mentions that team management did not take his crashes seriously (as they weren’t captured on camera), leading to him being sent back out and Mercedes opting not to withdraw.

      The two undamaged cars started the race, although Mercedes made some adjustments (with contributions from Adrian Newey) and advised drivers to keep their distance from other cars at high speeds. However, this wasn’t sufficient to avert Peter Dumbreck’s crash during the race—one of the most replayed moments in motorsport history.

      That incident stemmed from an imbalance in downforce distribution between the front and rear of the car. The low-rake setup reduced front-end downforce, while the fixed rear wing did not yield a corresponding decrease at the back. This configuration caused the front to lift on the bumpy Circuit de la Sarthe, allowing more air to flow beneath it and elevate the front, while the rear wing maintained downward pressure. Additionally, the turbulence from a preceding car exacerbated the situation.

      Just as no battle strategy survives engagement with the enemy, even the most ingenious engineering ideas may fail in practice. A painful reminder of this is currently being felt by Aston Martin and Honda in F1, although at least the nerve-wracking AMR26 hasn’t taken flight.