I am using my maruti 800 on lpg from last 2 years. My maruti fuel consumption on pertrol is 20 km per liter on petrol but when I drove the same on LPG Maruti gives same 20 km per liter on LPG, but as cost facter LPG is half price from pertol.

It is also low maintence cost for driven maruti on LPG. that is the additional benefit.

But it has some other side that is when we drive maruti 800 on LPG we did not get pickup like petrol driven car. Also some (very few) starting problem in some cars which is not maintaned properly.

You may visit http://www.autogas-india.com/eco.html for more details required in this issue.

Cars on LPG/CNG are highly economical to run and the expenditure is almost 1/3 to that of Petrol.

The total cost of the conversion can be recovered quickly from the savings accruing by use of Autogas in lieu of Petrol depending on the average run of the car.
 
Moreover, gas being a cleaner and greener fuel in comparison to Petrol / Diesel there is less wear and tear of the engine. There is much less carbon deposit on the engine and also the life of Engine oil is enhanced which does not dilute.
 
One can say that on a whole 15% of car maintenance costs are saved by using Autogas.

Besides economy, there is no compromise to the safety & performance of the car which is the same as Petrol.
 
Engine runs smoother and there is no change in the noise or vibration of the car which is a major plus over diesel cars.