Should you fit a CNG kit in your car?
Cars that run on CNG are much cheaper in the long run, provided you drive regularly, but its few disadvantages may spoil the fun. Find out if you’re making the right decision.
If you’re feeling the pinch of running your car every day, you could consider installing a CNG kit in your car. It’s a much more economical fuel to run your car on, but it also has an upfront cost. Typically, a CNG kit would cost you anything between Rs25,000 to Rs50,000, depending on the tank you want and whether your engine is of the carburetted-type (in which case it would be cheaper) or uses the fuel-injection method. Before we tell you just how much you would save by switching to CNG, though, let’s examine its disadvantages.
Disadvantages of a CNG kit
Will take up boot space: This depends on the size of your car, but a CNG kit would occupy up to half of your boot. So if you tend to take long trips, with a lot of luggage, it’s not an idea to steer away from petrol.
Initial costs: The initial cost, as mentioned above, can be as high as Rs50,000. If you’re a very regular driver, you’ll recover your money in no time. But if you don’t drive very often, you need to be sure you’ll use the car for a few years. See the calculations below for a better idea about the numbers.
Insurance premium increase: CNG cars are perceived to be riskier by insurance companies. The Indian Motor Tariff, which prescribes charges for car insurance, says that companies could charge an additional Rs60 for a CNG vehicle, but the premium is usually 10% higher.
Time for refuelling: There aren’t very many CNG stations in most areas yet, which means that you’ll be in the same long line as rickshaw drivers. Anecdotal evidence suggests that it takes an average of 15 minutes to refuel.
Crunching the numbers
Example 1 – 1,000km per month/20km/l
Here we consider you get a mileage of 20km/l running on petrol, and that CNG costs Rs40/kg and petrol Rs83/l (in Mumbai). Our calculations are for travelling about 1000km per month.
9kg of CNG will give you a range of about 150km. This comes out to about 60kg of CNG (for 1000km) required per month. So it would cost you about Rs2,400 to run on CNG per month.
Now, 1000km per month means that you would have to buy 50 litres of petrol every month, which translates into an expenditure of Rs4,150 per month on petrol.
Thus, using CNG, your travel expenses would be reduced by over 40% of the total amount you’d spend if you used petrol.
Investment recovery*: According to the estimates in our first example, you would save Rs1,750 per month and Rs21,000 every year, which means it would take you a little over two years to get back your initial investment.
Example 2 – 750km per month/15km/l
Here we consider a slightly more realistic scenario. So petrol mileage is taken as 15km/l and we assume you travel about 750km every month. The cost of CNG and petrol (in Mumbai) remains the same.
Again, with 750km per month at a mileage of 15km/l, you would need 50 litres of petrol every month which comes to Rs4,150/month.
The reduced range every month means that you would need just 45kg of CNG per month. And at a rate of Rs40/kg, your monthly fuel expenses would then be Rs1,800.
This means your travel expenses would be reduced by 55% every month with CNG.
Investment recovery*: These results indicate that you would save Rs2,350 every month and about Rs28,000 every year. So you could make up your initial cost in little under two years.
Example 3 – 500km per month/15km/l
Here we assume that petrol mileage is about 15km/l and monthly travel is around 500km. The cost of CNG and petrol (in Mumbai) remains the same.
Travelling 500km every month would mean you’d need about 33.5 litres of petrol monthly. This would cost you about Rs2,780 per month.
At this range, just 30kg of CNG would suffice every month, leading to a monthly CNG cost of Rs1,200.
Again, your cost would be around 55% of the monthly cost.
Investment recovery*: With a highly reduced range, it becomes less feasible to switch to CNG. You would save only about Rs1,580 per month and slightly less than Rs19,000 a year. You would have to wait over two years to break even.
*Our calculations keep the CNG mileage (range) constant. This is an oversimplified situation, and in reality, the lower your mileage with petrol, the lower your CNG range.