Government’s big disclosure on E20 petrol: ‘Fuel alone does not reduce the mileage of vehicles’, know the real reasons for falling mileage and easy formulas to increase the average of the vehicle.

With the increase in availability of 20 percent ethanol blended petrol (E20) at petrol pumps across the country, a new debate regarding mileage had erupted among the drivers. From social media to automobile forums, it was being claimed that the mileage of vehicles has dropped by 15 to 20 percent due to the use of E20 fuel. Amidst these claims and growing concerns of consumers, the Ministry of Petroleum and Natural Gas and automobile experts have clarified the situation with technical evidence.

Technical analysis released by the government and studies by the Automotive Research Association of India (ARAI) have made it clear that E20 petrol alone is not responsible for the huge decline in mileage of any vehicle. Many other mechanical, environmental and human factors are at play in driving mileage in real driving conditions, which are often ignored.

What is E20 petrol and how much does it affect the mileage?

E20 fuel contains a mixture of 80 percent conventional gasoline (petrol) and 20 percent bio-ethanol. Ethanol is a renewable fuel produced from sugarcane, corn and surplus food grains. The main objective of rapid implementation of this policy by the Government of India is to drastically reduce the import bill of crude oil, save foreign exchange and clean the environment by reducing carbon emissions from vehicles.

From the scientific point of view of energy density, the energy density of pure ethanol is about one-third less than that of normal petrol. When 20 percent ethanol is added to petrol, there is only a slight reduction of 3 to 6 percent in the energy density of the overall blend. Automobile tests have shown that even if a vehicle is not specifically calibrated for E20, mileage may vary by at most 2 to 5 percent. For example, if a car gives a mileage of 20 km per liter, due to E20 it may come down to 19 or 19.2 km and not 14 or 15 km. In such a situation, there are other major reasons behind the huge drop of 20 to 30 percent in mileage.

Not just fuel, vehicle mileage suddenly drops due to these 5 big reasons

The mileage of a vehicle does not depend only on the oil put in the tank, but is directly related to the way the vehicle is maintained and driven. Experts have outlined the 5 main factors that affect mileage the most:

• Aggressive driving and wrong gear shifting: Repeatedly pressing the accelerator suddenly (hard acceleration), applying sudden brakes at high speed and pulling the vehicle in wrong gear are the biggest reasons for falling mileage. Using a higher gear at low speed or a lower gear at high speed puts excessive load on the engine, due to which fuel consumption increases by 20 to 30 percent.

• Under-inflated Tyres: If tires are underinflated by just 2 to 3 pounds below the recommended PSI, rolling resistance (friction) between the road and the tire increases. Due to this, the engine has to use double the power to rotate the wheels, which directly reduces the mileage by 5 to 10 percent.

• Bumper-to-bumper traffic and excessive idling: In big cities, during heavy traffic jams, continuous idling of the vehicle and frequent shifting from first to second gear consumes a huge amount of petrol. Keeping the AC on without switching off the vehicle for more than 1 minute at a traffic signal or in a traffic jam burns approximately 0.8 to 1.2 liters of petrol per hour.

• Poor maintenance and dirty spark plugs or air filter: When the engine’s air filter gets clogged with dust and dirt, the engine does not get enough oxygen for combustion. Due to this, the engine starts working on ‘rich fuel mix’, that is, less air and more petrol is burnt. Apart from this, due to old engine oil and bad spark plugs, the combustion cycle remains incomplete, which leads to a direct decline in mileage.

• Excess weight on vehicle and excessive use of AC: Constantly carrying heavy non-essential items in the trunk of the vehicle and installing a roof rack increases the aerodynamic drag. Also, running the air conditioner continuously at minimum temperature in extreme heat puts excessive load on the engine compressor, which can reduce mileage by 10 to 15 percent.

Impact of E20 on older vehicles (BS4 and early BS6)

There was also a question in the minds of consumers whether E20 petrol could harm the engines of their old vehicles. According to automobile engineers, all new vehicles manufactured after April 2023 (BS6 Phase 2 / RDE norms) are fully E20 material-compatible.

In older vehicles (BS4 or earlier models) the rubber hoses, fuel lines and gaskets were designed as per conventional petrol. Ethanol has a tendency to absorb moisture (hygroscopic nature), which can affect some rubber parts of older vehicles in the long run. However, the modern automobile industry has clarified that by regularly driving the vehicle and getting the fuel filter and pipes checked on time, the risk of any serious fault even in older vehicles becomes negligible.

4 easy practical tips to increase vehicle mileage by 20 to 25%

If you want to achieve maximum fuel economy from your vehicle, you can adopt these easy and effective driving habits:

• Maintain economy speed (45 to 60 km/hr): Drive the car at a steady speed on highways and open city roads. Use cruise control wisely and avoid unnecessary overtaking.

• Tire pressure check once a week: Always inflate cold tires (before driving) as per the standard recommended by the company. Use of nitrogen is helpful in keeping tire pressure stable.

• Timely servicing and right grade engine oil: The engine oil, oil filter and air filter must be changed as per the manufacturer’s instructions. Synthetic oil of the right viscosity grade increases mileage by reducing friction.

• Smart driving in traffic: If you wait more than 30 seconds for a red light, turn off the engine. Always keep this feature on in vehicles with auto start-stop technology.

Big step towards green future and self-reliant India

Ethanol blending program is not just an alternative fuel strategy but it is a revolutionary step linking the country’s agriculture sector with the energy sector. Lakhs of sugarcane and grain producing farmers of the country are getting direct economic benefits from ethanol purchase.

The government and automobile experts have a clear message that consumers should not fall into any kind of confusion or misleading publicity regarding E20 petrol. By adopting proper vehicle care, balanced driving behavior and regular technical checks, best mileage and smooth driving experience can be achieved even with E20 fuel.