Short answer: an e-bike usually has the lower energy and routine-maintenance cost per kilometre, but it is not automatically the cheaper purchase. The honest comparison includes electricity, petrol, tyres, service, battery reserve, financing, registration, downtime and the difference in purchase price.
Start with the same journey
Use the same annual distance, rider load and route. For an e-bike, calculate wall energy: battery nominal Wh × charger and battery losses ÷ real range. For a petrol bike, divide litres used by distance and multiply by the current pump price. Do not compare a laboratory range with a traffic-tested petrol figure.
| Cost line | E-bike | Petrol bike |
|---|---|---|
| Energy | Electricity in kWh × tariff | Litres × pump price |
| Routine maintenance | Tyres, brakes, bearings, electrical checks | Oil, filters, plugs, chain, clutch, tyres and brakes |
| Major reserve | Battery, charger, BMS or controller | Engine, clutch, exhaust or fuel-system repairs |
| Time cost | Charging and service downtime | Fuel stops and service downtime |
A transparent Bangladesh example
Assume 12,000 km per year. Suppose an e-bike consumes 35 Wh/km from the wall and charging costs ৳11.36/kWh: energy is about ৳4,771/year. Suppose a petrol bike returns 45 km/L and petrol is ৳160/L: energy is about ৳42,667/year. These are illustrative assumptions, not a promise; change either input in the calculator and the result changes immediately.
Add maintenance and a battery reserve. If the e-bike battery costs ৳70,000 and you conservatively budget one replacement over five years, reserve ৳14,000/year. If the petrol bike needs ৳12,000/year of routine service, the gap narrows but may still favour electric. Purchase-price difference, financing and resale can reverse the conclusion.
Break-even calculation
Annual saving = petrol energy + petrol maintenance − e-bike energy − e-bike maintenance − battery reserve. Divide the e-bike purchase premium by annual saving. If the answer is three years, the e-bike must remain healthy and useful for at least three years before the premium is recovered.
Where the headline can fail
- Charging from a commercial station may cost more than home charging.
- A weak or overloaded battery can turn a 35 Wh/km estimate into a much higher figure.
- Replacing a lead-acid set early can erase several years of energy savings.
- Battery warranty, dealer support and resale value are financial inputs, not footnotes.
Verdict
Choose electric when your route fits the real range, you can charge safely and the battery warranty is credible. Choose petrol when you need rapid refuelling, long-distance flexibility or service coverage that the local EV ecosystem cannot yet provide. Use your own measured km, tariff, fuel receipt and written battery price for the final decision.