Largest smallest-engined car...

[AJS-]

Eighteeteewhy said:

I've got it!...

That was predictable.

[nickbee]

I had a VW Touran hire car with a 1.2 engine, which is a big car with a small engine.

The smallest cars I've owned were 1.8, although I've never been without a car of two litres or more. I'm not going to bother with the weird scoring as a) it's nonsense and b) I'm pretty sure the OP got it wrong at the outset!