It's not uncommon for performance cars to be faster than manufacturers claim. In particular, German manufacturers have a habit of sandbagging performance figures. Officially, the 2021 BMW M550i's 4.4-liter twin-turbo V8 is rated at 523 hp and 553 lb-ft, but RaceChip discovered it generates 526 hp and 568 lb-ft of torque when hooked up to a dyno.

It's the same story for the M5, which is also more powerful than BMW claims. According to BMW, the M550i will hit 0-60 mph in 3.6 seconds. You would think the M550i would be a few tenths of a second faster than advertised given that it's more powerful than BMW claims, but Car and Driver found its performance was slower than expected.

During a test drive, the fastest 0-60 mph time set was 4.1 seconds. A second test brought the sprint time down by a few tenths of a second to 3.9 seconds. We doubt many would complain about this level of performance in a large four-door sedan, but this is still slower than BMW's official performance specifications. BMW has investigated the issue and has discovered that a software issue is to blame for the M550i's slower performance. According to BMW, the problem is caused by a "communication error" between the engine computer and the stability control system.

This causes a drop in turbocharger boost pressure, resulting in slower 0-60 mph times than advertised. To fix this performance problem, BMW will release an over-the-air software update in the summer to unlock the car's full potential, so you won't even need to visit a dealership to get it fixed.

Once installed, the M550i will be able to hit 0-60 mph in 3.6 seconds as BMW claims. BMW also discovered the same issue is affecting the 2021 540i xDrive, which will also be fixed in an upcoming software update.