Ford Courier Engine Problems

The rule of thumb is that a vehicle would use around 20 per cent more LPG than it would use of running on petrol. On average a 1996 Ford Courier would do around 12.5L/100 km on petrol, which means it should do around 15L/100 km, or 6.6km/litre, on gas. On that basis yours is thirsty. On your second question, yes you would expect a car with fuel injection to be more economical than one with a carburetor.