The autonomy LPG car depends on the dimensions of tank installed, whose choice could be made in relation to the use of the car to privilege the load capacity or onmore autonomy of the car itself.
In case it desire privilege the load capacity it's advisable to install atoroidal tank that is placed on the car's spare wheel compartment and keeps unchanged the load capacity. If the route with gasoline is 10 km/lt with gas will be about 9.5 km/lt.
The tanks can be of different shapes and sizes so different autonomies. To have aindicative reference, with a 40 liter tank (32 lt effective LPG following the intervention of the safety valve) our car would have an autonomy about 290 km, instead with a 60 liter tank where it is possible insert 48 lt effective of LPG the autonomy will be about 480 km.