I have had my FX since 1987. It is a 1985 Japan Assembled model with 1987 registration. My affections for the car knows no bounds. It still gets up to 120K.
I feel FX is all-round a better car than Mehran. I know because I had my father's '96 Mehran to compare it with.
I have always kept it on petrol. Never installed CNG. Probably that is why in all these years it has undergone one complete overhaul and once only gasket & rings changed.
The fastest I ever could get out of my FX was slightly less than 130K. That too in the early 90s when the car is still quite new.
But that is not the issue here. The issue is the claim that it does 18KM/liter. I have never experienced that sort of a mileage in almost 2 decades from my FX. Even on the highways it never gave more than 15+KM/liter. Now-a-days around 13+Km/liter on highway. That is the honest truth.
No FX owner that I personally know claims anything remotely similar.
@deathrider's FX must have something special under the hood.