Automotive performance has been in a state of Line Go Up for decades now. More power, more grip—more weight. But we might be finally hitting a plateau with the 2025 BMW M5, which has 117 horsepower more than its predecessor. Nice! So how about curb weight? That’s coming down a bunch, right? … Guys?
BMW makes a small fuss about how much effort it put into trimming weight off the all-new M5. It lightened the transmission and transfer case, and replaced the oil pan with a plastic one to cut mass. (Saving money seems like the big consideration there, though.) It also offers an optional carbon fiber roof that cuts out 66 pounds, as the standard one is presumably made from depleted uranium. Available carbon ceramic brakes eliminate another 55 lbs, all of it rotating mass. But neither offset the M5’s immense weight gain.
Just so you know what we’re coming from, the last-gen M5 came in at 4,345 lbs when it was updated in 2021. Hefty, but not that outlandish in a world with the Dodge Charger Hellcat. But the new 2025 M5 weights 5,390 lbs, which is a 1,045-lb weight gain, or 24 percent. That’s about the same margin of weight I gained in that same period, and between the two of us, I’m the only one that can stress-eat.
Some of that added mass comes from the new M5’s hybrid system, which amps up total output to 717 horsepower and 738 lb-ft of torque. But while the last-gen M5 made just 600 hp and 553 lb-ft, it still had a better power-to-weight ratio. As a result, the new M5 is slower from zero to 60 mph: It takes 3.4 seconds, whereas the 2021 took just 3.2. Or, if you bought the Honda Accord-like M5 Competition, just 3.1.
What really underscores the M5’s weight gain is comparing it to the new 2025 X5, which is no welterweight at 4,998 lbs. But it’s a midsize premium crossover, not a performance sedan. BMW must be really holding back its best for the inevitable faster versions of the M5 it has waiting in the wings. They’re gonna need more carbon fiber than the entire Formula 1 grid combined to help out the heavy new M5, though.
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