Have you noticed something strange lately? Maybe your car’s fuel efficiency display is showing 12 km/l instead of the usual 14 km/l. You aren't imagining it. The fuel has changed.
As of late 2025, India has fully rolled out E20 Petrol (a blend of 20% Ethanol). While green, it has a side effect dealerships aren't advertising: Ethanol has 30% less energy density than pure petrol.
Today, Volt Roam investigates the real-world impact of E20 and asks: Is this the "push" you finally needed to buy an EV?
The "Hidden Tax": Why E20 Drops Your Mileage
Let’s get technical. Pure petrol creates massive heat energy. Ethanol burns cleaner but cooler. It packs less "bang" per liter.
The Result: To generate the same power, your engine injects more E20. Recent tests show a 3% to 5% drop in mileage. Over 5 years, that is thousands of rupees vanishing.
The Corrosion Fear: Is Your Pre-2023 Car Safe?
Warning for Older Car Owners
Cars made before April 2023 may not be E20 compliant. Ethanol absorbs moisture and can corrode rubber fuel hoses over time. While the government says it's "safe enough," the risk of long-term engine wear is real.
The Math Showdown: Petrol vs. EV in 2026
Does the EV math finally make sense? Let's compare the Tata Nexon (Petrol vs EV) for a user driving 1,200 km/month.
| Feature | Nexon Petrol (Smart) | Nexon.ev (Creative) |
|---|---|---|
| On-Road Price | ₹ 9.80 Lakh | ₹ 13.50 Lakh |
| Real Mileage/Range | 12 km/l (E20) | 300 km (Real) |
| Running Cost/KM | ₹ 8.60 / km | ₹ 1.20 / km |
| 5-Year Fuel Cost | ₹ 6.20 Lakh | ₹ 86,400 |
| Total 5-Year Cost | ₹ 16.60 Lakh | ₹ 14.61 Lakh |
Verdict: Even though the EV costs more upfront, you save approx ₹2 Lakhs over 5 years compared to an E20 petrol car.
Volt Roam Buying Advice
- Stick to Petrol IF: You drive less than 500 km/month or live in a remote area with no chargers.
- Switch to EV IF: You drive 40+ km daily or own a pre-2020 car that might suffer from E20 corrosion. Trade it in while resale value is high.
