Although dynamometers are thoroughly unpredictable, since comparing systems and individual examples and even on the same car across time can be truly difficult, they serve to provide a rough figure. The latest dynamometer tests on a 2009 BMW 750i shows some truly interesting figures.
The dynamometer result showed wheel horsepower and torque numbers were very near the bench figures claimed for the car. With the 4.4-liter twin-turbo V8 on a Dynojet chassis dyno, the car pumped up 391hp (292kW) and 434lb-ft (588Nm) of torque.
There is also a slight disparity between the RPM numbers from the carmaker's claimed maximums, achieved at 5,200rpm, a matter of 300rpm earlier and torque by 1,500rpm, which is 3,300rpm late.
Torque curve is still nicely flat from around 2,500rpm to 4,600rpm, offering an abundance of punch in the middle range, where it will be more observable on the road.
So instead of creating doubt concerning its performance capabilities, the fact is, it cements it. The numbers it posted mirrors crank potency near 450hp (335kW) and 510lb-ft (691Nm) of torque, the 750i is, although it has a large footprint and looks daunting, a typical sleeper, which is sufficiently fast enough to finish the sprint to 60mph in 5.2 seconds at 103.7mph.
Surely, the flat power curve and remarkable speed are the results of turbocharging.