How to measure your bike's real mileage

Every cost calculation for a petrol two-wheeler starts with mileage, and the number on the brochure is not the one you get on the road. It is measured on a test cycle in a lab. Stop-start traffic, a pillion, tyre pressure and how hard you open the throttle all pull the real figure down.

Measuring your own takes two visits to the petrol pump and no tools.

The tank-to-tank method

1. Fill the tank to the brim. Ask for a full tank, not a fixed amount. Note the odometer reading (or reset the trip meter).
2. Ride normally. Use the bike the way you always do until the tank is around a quarter full. Do not change your riding to “save fuel” — you want the everyday number.
3. Fill to the brim again, at the same pump if you can, and note the litres this second fill took and the new odometer reading.
4. Divide. Kilometres ridden between the two fills ÷ litres in the second fill = your real km per litre.

For example: 312 km between fills, and the second fill took 7.4 litres. 312 ÷ 7.4 = 42.2 km/l.

Make it more accurate

• Repeat it two or three times and take the average. One tank can be skewed by a long highway ride or a week of jams.
• Use the same pump and the same nozzle where you can. Pumps cut off at slightly different levels.
• Keep the bike upright on the main stand when filling, so the tank fills the same way each time.

Why it matters

A few km/l either way changes your monthly petrol bill more than you might expect. If you ride 30 km a day for 22 days, at ₹100 a litre the difference between 50 km/l and 40 km/l is ₹330 a month — about ₹4,000 a year.

Once you have your number, put it into the commute cost calculator to see what your ride really costs, or into the petrol vs EV calculator to see whether going electric would pay off for you.