BMW, Porsche, Mercedes, and Audi build some of the most potent models available for mainstream consumers. Their big V8 engines make copious amounts of horsepower and torque, with the automakers claiming some big power figures. A new Carwow video puts their claims to the test by pulling the M5 Competition, E63 S, RS6, and Panamera Turbo S E-Hybrid onto the dyno and running the numbers to find out their actual power-to-weight ratios.

The most powerful car in attendance was the Porsche. The Panamera’s hybrid powertrain with the 4.0-litre twin-turbo V8 engine produces 700 bhp and 641 lb-ft of torque. The automaker claims the car weighs 2,350 kilograms. The BMW M5 Competition is the second-most powerful model in the test, sporting a larger twin-turbocharged 4.4-litre V8. However, the non-hybrid saloon makes 625 bhp and 553 lb-ft of torque. It’s the lightest, too, at 1,940 kg.

Gallery: 2021 Porsche Panamera Turbo S: First Drive

The Mercedes-AMG E63 S features a twin-turbo 4.0-litre V8 engine making 612 bhp and 626 lb-ft of torque. Mercedes says the high-powered E-Class weighs 2,010 kg. The Audi RS6 trails the rest of the field in power even though it also sports a twin-turbo 4.0-litre V8 engine. The powertrain produces 600 bhp and 590 lb-ft of torque. It weighs 2,075 kg.

The results were all over the place. The Audi delivered 599 bhp and 603 lb-ft of torque from the engine on the dyno, while the BMW surpassed its claimed figures to return 652 bhp and 636 lb-ft. The Mercedes also made more power than the manufacturer claimed, producing 636 bhp and 690 lb-ft. The Panamera Turbo S E-Hybrid also beat its expectations with 750 bhp and 681 lb-ft of twist.

The dyno results were only one part of the test, with Carwow recalculating their power-to-weigh ratios after pulling the cars onto the scales. The results put the Audi in last at 270 bhp/tonne. Mercedes took third at 305 bhp/tonne. While the Porsche was the most powerful car, it only achieved second with its 309 bhp/tonne rating. The BMW took first thanks to making more power and weighing less than the automaker’s claim returning a 340 bhp/tonne rating.