[CalvinC]

Use the vehicle's ID, not the model id.

pawn Код:

if(IsATruck(o)) Fuel[o] = 100.00;
else if(IsABus(o)) Fuel[o] = 80.00;
else if(IsABike(o)) Fuel[o] = 15.00;

Like this.
You were trying to pass on the model id as the vehicle id, which would just be the same as:

pawn Код:

GetVehicleModel(GetVehicleModel(vehicleid))

Which wont work.