I am a used car importer in Karachi
First off I would suggest you dont buy yourself a 660cc car, They say it will give you bla bla fuel but come to think of it, 660cc engine can only generate a certain power & when you put the wait of x car on small engine, it is obvious it will need more power to drag the weight meaning more fuel burned.
On the other hand if you get yourself a 1000cc Car (ideal these days Passo) then your car has an engine which is easily able to support its weight thus you will get better fuel efficiency.
With that I rest my case that 1000 cc car is better if you are considering fuel economy.
I would also say that a 100,000 kms driven JDM car is 10 times better than a local piece of junk, in Japan, unlike our country they have certain rules that they follow before a car is allowed on the road. After a certain millage a car is supposed to get a certain maintenance done provided if the work is required or not. Unlike here where "sub chalta hai" so any sane person will understand that millage doesn't matter if a car is properly maintained however our idiotic nation doesn't understand such a simple thing.
If you need any help sourcing a car then you can get back to me on 0321 928 3186
peace