why do some smaller engines have lower gas mileage than some larger engines?

Question

why do some smaller engines have lower gas mileage than some larger engines?

In: 208

Answer 1

I recall a Top Gear where a BMW 3ltr was against a Toyota Prius Paris to London.
the Beemer was just ticking over but the Prius was being thrashed at the same speed.
unsurprisingly for motorway driving the Beemer is a better car