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E20 vs E10 petrol: what's the difference?
The jump from E10 to E20 doubled the ethanol in India's petrol - from 10% to 20%. For most drivers the day-to-day difference is small, but it's real. Here's the honest side-by-side.
| Factor | E10 | E20 |
|---|---|---|
| Ethanol content | 10% | 20% |
| Energy per litre | Higher | Slightly lower |
| Typical mileage impact | Baseline | ~1–6% lower (more on older vehicles) |
| Octane / anti-knock | Good | Higher octane |
| Emissions (CO, HC) | Baseline | Lower |
| Fuel-system wear (older cars) | Lower | Slightly higher over time |
| Availability in India | Phased out | Standard since April 2025 |
Is E20 worse than E10?
Not in every way. E20 has a higher octane rating (better anti-knock) and cleaner combustion, and it supports India's energy-security and farmer-income goals. The trade-off is a small mileage reduction and, for older vehicles, some extra attention to fuel-system parts.
What it means for you
- New vehicle (2023+): practically no difference - it's built for E20.
- Older vehicle (pre-2023): expect a modest mileage dip; keep up with servicing.
Find your vehicle's exact standing with the E20 Compatibility Checker, and estimate the cost with the Mileage Calculator.