With good reason, BMW has made a big deal about how the engineers were able to shave off 100 kilograms (220 pounds) from the rear-wheel-drive M4 Competition to create the CSL. The track-focused coupe weighs 1,625 kg following the Draconian diet, while the inline-six engine has been massaged to produce an extra 40 hp for a grand total of 550 hp.

While you’d be tempted to think these changes would be enough to give the CSL the best power-to-weight ratio among all BMWs, that’s actually not the case. Our German colleagues at Bimmer Today crunched the numbers and concluded the flagship M4 with its power-to-weight ratio of 1 hp / 2,95 kg trails behind the M5 CS. As the table below shows, the now-defunct super sedan moves 2,87 kg with one horsepower.

If we’re strictly talking about the power-to-weight ratio, the M4 CSL represents a massive improvement compared to its predecessor, the M3 CSL. The top-tier E46 model had 360 hp on tap in a car that weighed 1,385 kg, resulting in a ratio of 1 hp for 3,84 kg. Of course, we can’t simply ignore the fact the CSL has put on 240 kg over the years, but that’s a different story.

Image: BimmerToday.de

Is there a car that has the potential to dethrone the M5 CS? Yes, there is. We’re talking about the modern-day 3.0 CSL arriving before the end of the year. If our sources are correct, it’s going to pack somewhere in the region of 600 horsepower. The rumored manual gearbox should further improve the power-to-weight ratio since logic tells us its stick shift will be a smidge lighter than the automatic.

However, there are a couple of problems with the 3.0 CSL (official name or so we’ve heard). First, it’s going to be the most expensive new BMW ever, at approximately €750,000 a pop. Second, availability will be extremely limited as word on the street says only 50 cars will be made. The M5 CS also had a relatively short life cycle since it was built for just one year.

Source: Bimmer Today