Engine Size v. Fuel economy

Searched for this but found nothing.

I drive a 1.8 Laguna and I find that the petrol consumption is very high. I was wondering if anyone could tell me if there is a large difference in fuel consumption between a 1.8l and say a 1.4l. If it's possible to quantify this so much the better.

It depends on the size and weight of the car more than the engine size.

A 1.8 laguna may well do better than a 1.6 laguna because the 1.6 is working harder more of the time to pull the weight.

a 1.4 corsa will do better than a 1.4 astra.

If you want to cut fuel bills get a small diesel.

Something like the polo diesel should have great mpg.