E20 Petrol Controversy: Mercedes-Benz Responds After Sourav Joshi's Mileage Claim

The 'E' stands for Ethanol, while the number 20 stands for the exact percentage of Ethanol mixed into the fuel.

It is part of a global and national initiative, most notably headed by the Government of India, to reduce reliance on imported crude oil and lower greenhouse gas emissions.

Technical Composition And Properties

Ethanol is a clear, colourless liquid biofuel, a renewable alcohol fuel produced from crops such as sugarcane, damaged food grains, molasses, maize (corn), and surplus rice.

It has a high natural octane rating (around 108). Blending it into petrol increases the overall octane rating of E20 fuel, which helps prevent engine knocking and improves combustion efficiency.

It contains one-third less energy than pure petrol; as a result, lower-energy vehicles running on E20 experience a minor 3% to 5% drop in fuel efficiency.

Why Vehicle Compatibility Matters?

Ethanol is highly hygroscopic, absorbing water from the air, and corrosive, which can degrade certain materials if vehicles are not designed for it.

Modern Vehicles have upgraded fuel systems that are chemically treated to resist ethanol corrosion.

Their Engine Control Units (ECUs) are also calibrated to adjust air-fuel ratios for optimal combustion.

Older legacy vehicles, especially those built before 2020-2023, use standard rubber and metal components.

Using E20 consistently in an incompatible engine can cause those rubber lines to crack, corrode aluminium components in the fuel tank and potentially clog the fuel injectors.

Mercedes-Benz India's Response

Mercedes-Benz India responded publicly to the viral claims. The company clarified that all of its BS VI petrol vehicles sold in India are designed, tested, and certified to operate safely on E20 petrol.

According to Mercedes-Benz, the E20 petrol itself would not be the cause of such an extreme reduction in fuel economy.

The company also explained that fuel efficiency depends on many different factors, including:

• Engine health

• Driving style

• Traffic conditions

• Air-conditioning usage

• Tyre pressure

• Vehicle load

• Fuel quality

• Sensor or mechanical issues

Mercedes-Benz stated that a sudden drop from around 17 km/l to 5 km/l would be highly unusual and warranted a technical inspection rather than immediately blaming the fuel.

The statement reads, "At Mercedes-Benz, customer safety, vehicle reliability and performance are of paramount importance to us.

All Mercedes-Benz petrol BS VI vehicles are compatible with E20 fuel and are certified accordingly by the relevant authorities. We are happy to support customers with any technical queries. Mercedes-Benz remains committed to sustainable mobility."

The U-Turn And Apology

Following the official corporate pushback, Sourav Joshi took his SUV to an authorized Mercedes-Benz service centre and issued a complete retraction.

Diagnosis revealed that the drop in mileage was caused by an isolated mechanical engine/sensor issue, completely unrelated to the chemical makeup of E20 petrol.

Joshi posted a public apology stating: "We visited the Mercedes service centre, and they found that there was an issue with the engine, which was causing the low mileage. I apologize for the misunderstanding regarding E20 petrol."

And he immediately removed or edited the misleading segment from his vlog.

Do Other Countries Use Ethanol-Blended Petrol?

Absolutely. India is far from the first country to adopt the ethanol-blended fuel.

Several countries have used ethanol blends for many years.

Brazil is considered the global leader in using ethanol-blended fuel; regular petrol already contains a high percentage of Ethanol, and Brazilian vehicles are 'flex-fuel models' that are capable of running on petrol, high-ethanol blends, or nearly pure Ethanol.

The United States commonly sells E10 nationwide, while E15 is increasingly available.

Flex-fuel vehicles can also operate on E85, which contains up to 85% ethanol.

Drivers in other countries also experience a small decrease in fuel economy when using higher ethanol blends, as Ethanol contains less energy per unit than petrol.

E20 petrol is not a perfect fuel; it delivers slightly lower mileage than pure petrol. However, for vehicles designed and certified to use it, that reduction is generally small and expected.