I have a khyber in good condition only 40k done driven (economical never racing type driving) and maintained (caltax oil + fuel filter at every 2500 km, tuning and original denso plugs* changed at 10,000km cng tuned every 5000 km).
i bought it only at 10k installed cng at 25k and it is driven in sialkot(i mean small city and small trips are ALWAYS done on petrol). it's 99 model although it needs a little bodywork (scratches and paint) but engine is in A-1 condition. my father drives a 2.0d saloon 2002 now(only 55000k done by my uncle). I have driven other cars but khyber is da best.
on cng it all depends on how cng is installed (idle throttle adjusted same as petrol, mixture should not be too lean or rich, hot water pipe should be installed, settings should be adjust if got a push button type lendirenzo switch, and wiring should be done neatly, timing should be advanced a bit ( we drive less on cng so it's not changed) i have driven many other cars the only car that can beat khyber is cultus efi.
here is hp rating of engines
Santro 40 hp
Cultus 45 hp
Khyber 48 hp
Cultus EFi around 60
Alto i dont know but it is less than cultus its gearing is more aggressive (short ratios less top speed)
Coure 35 hp (less weight is advantage)
a little lecture on engines
santro's engines is for smooth drive(not the racing smooth but good on ac and weight)
Khyber's engine is very good at acclerating,ac,smooth(needs clutch less often)
Cultus: good engine but under powered for weight of the car
Cultus efi: perfect engine for cultus's body
alto: what you want from old potohar's engine
coure: somewaht standard but ac unit is not good i mean we should not blame engine for low performance of ac.
my num
03456756804
03368614818
they r off at present coz my i dropped my fone in water