In India, mileage is one of the most important factors considered by car buyers. The main reason for this is, of course, rising fuel prices. Modern cars come with a fuel economy indicator in the dashboard to help you drive in the most fuel-efficient manner. But older cars didn't have them.
So how can we know the mileage on our own? Filling just one litre of fuel into a completely dry tank, and then checking how much the car can go is definitely not a wise approach.
If you know basic mathematics, you can easily calculate your car's average mileage. Here are some methods to find the fuel economy:
1. Distance Travelled Divided By The Amount Of Fuel Used
This method is the most convenient way to find your car's mileage:
- Drive your car to the nearest petrol pump.
- Note down the kilometres shown on your odometer (say, O1) and the level of fuel shown on the gauge.
- Fill up the tank.
- Note down the amount of fuel you've put in.
- Driving on a stretch gives more accurate results than using your car on alternate times or days.
- Now when the fuel gauge shows the reading you had previously recorded, notice the odometer reading (say, O2).
- Now subtract the new odometre-reading from the previous reading i.e. O2 -- O1.
- Divide the result got by the amount of fuel you had previously put in the car.
- The result is your mileage.
For example, if you've filled your car with 20 litres of petrol at a certain point indicated by the needle of the fuel gauge, and you've travelled a distance of 280 kilometres until the needle rests in the same position, your mileage is: 280/20 = 14km/l
2. Finding The Average Fuel Efficiency
No car can give a constant mileage figure, since fuel consumption depends on a lot of factors. Mileage figures especially change with the way you drive. Using the AC also reduces the mileage since it puts load on the engine to function. So, to get an overall average idea of your car's mileage, follow these steps:
- The above method i.e Distance Travelled Divided By The Amount Of Fuel Used, should be done multiple times.
- Take the average of all those mileage figures.
This method helps give you a much more accurate figure. If you go to a destination at high speeds and return back at low speeds, the mileage reading would be different in both ways. Hence, calculating the average consumption over a long period gives you a better idea of your car's fuel efficiency.
3. Using Amount Of Fuel Purchased
Since fuel prices are high and we do not want to empty our pockets every time, it is wise to have an idea about the fuel usage of your car. To know the mileage using the amount of fuel purchased, follow these steps:
- Set the trip meter to zero after filling the fuel tank full.
- Keep it like that for a certain duration of time (maybe a week or even a month).
- During this time period, add fuel to the car whenever you like.
- Note down the amount of fuel put in each time.
- Once you've decided to calculate the fuel economy, fill up your tank full again.
- Now add up the total amount of fuel purchased.
- Note down the trip meter reading now.
- Divide the kilometre reading with the amount of fuel purchased.
- This will give the average mileage, using fuel purchased.
4. Finding Fuel Cost Per Kilometre
The method to find the fuel cost per one kilometre of driving is fairly straightforward. Check the current fuel price in the market. Find your car's mileage using any of the above-explained methods.
Fuel Cost Per Kilometer = Current Fuel Price / Average Mileage
Things To Note
As told earlier, mileage figures can never be constant; unless you drive keeping all parameters such as speed and acceleration constant.
In real-world conditions, this is almost impossible due to traffic, road conditions, uphills, downhills and most importantly, driving fashion. If the manufacturer of your car has claimed a mileage figure, you should be expecting something close to that. However, if the mileage of your car is very low compared to that, take the car for a checkup.
Thoughts On How To Calculate Mileage Of A Car
Although modern cars show real-time mileage-figures in the instrument console, it is always good to know the old-fashion way. Since your car's mileage depends on a lot of factors, it is always a compromise to get either good fuel economy or good performance. If your car does both, congratulations!
If it doesn't and you spend a good proportion of your income on fuel, here are some Tips To Get The Best Mileage From Your Car.