How much mileage does E20 cost you?
The mileage drop from E20 is small — roughly 1% to 6% depending on the vehicle — not the 7–10% sometimes claimed online. Estimates put it at about 1–2% for vehicles calibrated for E20 and around 3–6% for those not tuned for it, with industry body SIAM citing figures in the 2–4% range.
Why E20 lowers mileage at all
The reason is simple physics: ethanol contains less energy per litre than petrol. A litre of E20 therefore holds slightly less energy than a litre of pure petrol, so your engine burns marginally more fuel to travel the same distance. This is an inherent property of the fuel, not a fault in your vehicle, and it is why a small, consistent drop is normal and expected.
How much it costs in real terms
For most drivers the impact is a few rupees per tank. As a rough example, a car returning 18 km/l and driving 1,000 km a month with a 2% drop uses only about a litre more petrol per month. Newer, E20-tuned engines narrow the gap further, and the cleaner-burning blend brings a small emissions benefit in exchange. The cost calculator on our homepage lets you estimate the rupee impact using your own mileage, monthly running and local petrol price.
Which vehicles lose the most?
Vehicles specifically calibrated for E20 (many post-April-2023 models) see the smallest drop, typically 1–2%. Vehicles that are material-compatible but not tuned for the blend see a slightly larger reduction. Very old vehicles not designed for E20 may see the drop toward the higher end. Diesel and electric vehicles are unaffected entirely, since neither uses ethanol-blended petrol.
Can you reduce the mileage loss?
You cannot eliminate the small energy-density difference, but good driving habits and maintenance help: correct tyre pressure, regular servicing, a clean air filter, smooth acceleration and not carrying unnecessary weight all preserve mileage regardless of fuel. In a compatible vehicle, there is no benefit to seeking out ethanol-free premium fuel purely for mileage — the small saving rarely justifies the much higher price.
Check your exact car or bikeFrequently asked questions
Is the mileage loss from E20 permanent?
Do E20-tuned cars lose less mileage?
Is the mileage drop really 7–10%?
Please note: this guide is general information, not a compatibility certificate for your specific vehicle. The verdict from our checker is an estimate based on manufacturing date and brand — always confirm with the “E20” label inside your fuel flap, your owner’s manual, or an authorised service centre before relying on it. It is not legal proof.