Self-driving CNG cars offer significant savings on fuel costs. Despite rental rates being the same across all vehicles, you can save over 40%. Here's how: 1. CNG filling costs approximately 650 INR for one tank, providing a mileage of 250 km. 2. Let's compare this to renting a petrol car with a mileage of 18 km per liter. 3. For the same 250 km drive, you'd need to fill 13 liters of petrol, costing approximately 1326 INR. So, it's clear that opting for a CNG vehicle results in substantial fuel savings.