The myth for Kei class JDM vehicles being fuel sniffer vehicle is totally untrue. Kei class vehicles have 660 CC engine, size 12 wheels & 175 mm foot print tyres as OEM equipment, .[ Kei class 4x4 excluded ] such vehicles be it sedan hatch or pickup trucks are not allowed over highways / motorways by law internationally
Realistically speaking in Pakistan Kei class vehicle owners expect it to perform over 15 km/litre, Even under ideal circumstances it cannot CHURN out that much, while actual efficiency noticed & reported across this very forum is always under 14 km/litre in citywide driving, that too is very doubtful due to fact of cars being 3 year old land in Pakistan with no track record.
Manual or auto transmission KEI vehicle with decent maintenance history of fluid changes and light foot driving can cover 14+ km/litre or less in Pakistan. - Mazda Carol, Suzuki Alto, Nissan Pino, Mitsubishi Minica, Daihatsu Move etc etc belong to same class & engine capacity.
Anything over & above 12km/litre is very fair so please do not expect Bike sort of fuel efficiency from kei class 4 wheel vehicles
and please do not expect such vehicles to cross 120 kph with all grown up adults in the vehicle such attempt may lead to a disaster.