Cars $P$ and $Q$ each have a different engine. The power input from the fuel is identical for both engines. The engine in car $P$ has a higher efficiency than the engine in car $Q$. Which statement about the cars or their engines has to be true?
- ACar P has a higher maximum speed than car Q.
- BCar P has a lower maximum speed than car Q.
- CThe engine in car P uses less energy per hour than the engine in car Q.
- DThe engine in car P wastes less energy per hour than the engine in car Q.