[mywittyname]

Piston engines are quite simple and can be extremely reliable.

There is typically a trade-off between maintenance and replacement. Piston engines require on-going maintenance, but can last a really long time. Electric motors require almost no maintenance but need to be rebuilt/replaced more often.

[Gibbon1]

Your average gasoline engine is kaput after 5,000 hours. Same deal with standard automatic transmissions.

Electric motors, power electronics, and simple reduction gears can last 5-10 times longer.