Just about everyone knows weight is the enemy of performance, but to what extent does it negatively impact a sports car’s capabilities? The best way to prove it is by taking two cars from different brands that share the same engine with virtually identical outputs. In this case, it would have to be BMW’s B58 installed in the M440i and the Toyota GR Supra.

“Convertible” is the keyword because the M Performance 4 Series featured in the drag race has a folding fabric roof. The car weighs 3,977 pounds, which means it has to drag around an extra 580 lbs compared to the identically powered Japanese coupe. That’s a massive difference of 263 if you prefer kilograms, thus resulting in a significant loss of performance whether it’s off the line or in a roll race.

A new video from YouTuber Sam CarLegion illustrates the massive gap between the two cars despite sharing the turbocharged straight-six engine. The 3.0-liter gasoline mill puts out 382 horsepower in both cars, with the GR Supra packing an extra pound-feet of torque, at 369 lb-ft. Both have an eight-speed torque-convertor automatic sending power to the rear axle. While the Toyota is sold exclusively in RWD form, you can get the droptop BMW with an optional xDrive for an extra $2,000.

To the surprise of no one, the M440i Convertible lost both drag races and the roll race from 31 mph (50 km/h). Had it been the AWD version, the BMW might have stood a better chance seeing as how the xDrive model is three-tenths of a second quicker to 60 mph than its RWD counterpart. The outcome is understandable, not only because the 4er is much heavier, but it’s also larger than the Supra.

You can rest assured the much-criticized fifth generation of the BMW-powered Supra will be pitted against the new M2 once it will be out next year. That should even the odds since the smallest M car will be substantially lighter while also featuring six-cylinder power. The G87 will also be more powerful as we’re hearing it’s going to have around 450 hp even in base form. Competition, CS, or even CSL models will follow, while the Supra is also reportedly getting a hotter version badged as a GRMN.

[Source: SamCarLegion / YouTube]