Electric vs Petrol Cars: How Much of the Energy Reaches the Wheels?

Efficiency

fueleconomy.gov, run by Oak Ridge National Laboratory for the US Department of Energy and EPA, says EVs convert over 77% of the electrical energy from the grid to power at the wheels. Conventional gasoline vehicles only convert about 12% to 30% of the energy stored in gasoline to power at the wheels. NHTSA likewise lists 80%+ of available energy converted to drivable power for EVs.

Emissions, with a caveat

EVs emit no tailpipe pollutants, although the power plant producing the electricity may emit them. The US EPA says EVs typically have a smaller carbon footprint than gasoline cars even when accounting for charging electricity, but the amount varies widely depending on how local power is generated, for example coal or gas versus wind or solar.

Trade-offs fueleconomy.gov lists

• Range: EVs have a shorter range than most conventional vehicles, though it is improving. Most can travel more than 100 miles on a charge and some more than 200 or 400 miles.
• Recharge time: fully recharging a battery pack can take 3 to 12 hours, and even a fast charge to 80% can take 30 minutes.
• Battery life: a DOE study suggests batteries may last 12 to 15 years in moderate climates and 8 to 12 years in severe climates, but replacement may be costly.

Which is right for you?

The efficiency numbers favour electric, but the best choice depends on charging access, daily distance and local electricity sources. In Sri Lanka, also check the import taxes, which apply to electric vehicles too (see our surcharge post).

Fact-checked on 30 October 2026 against the sources listed below. Tax rules and prices change by gazette, so confirm with Sri Lanka Customs or the Ministry of Finance before you pay.