Look at Van's Blather here.

Bret Ludwig wrote:

Automobile engines
function well in their intended application: delivering low cruising
power in vehicles with well designed transmissions and power trains.
Using them successfully in an airplane requires continuous high power
outputs and reduction systems coupled to the propeller. This is
completely foreign to their design intent.

Join me for a drive in the off-peak hours on the Autobahn and then tell me
again that auto engines can't stand continuous high power output.

In German, there's even a word for that: "vollgasfest",
roughly "full-throttle safe", indicating that an engine is fit for
continuous operation at full throttle. Engines that aren't full-throttle
safe don't sell in Germany and are cause of ridicule, as FIAT had to learn
the hard way.

Anno.