What Are Flex-Fuel Vehicles? Working, Benefits & Drawbacks Explained

Team CARS24
Team CARS24

Updated on: 6th March, 2024 IST


The automotive industry is in constant pursuit of finding sustainable alternatives to petrol and diesel. Electricity as a power source is being put into use, but it defies the practicality of petrol and diesel. Another substitute that is impressing both carmakers and the government is ethanol. When blended with petrol, it suppresses the overall pollutant emissions. The acceptance of ethanol has led to the development of flex fuel vehicles.

This blog will tell you everything you must know about flex fuel and flex fuel vehicles. The benefits of using flex fuel vehicles, challenges associated with flex fuel’s applications and what are the upcoming flex fuel vehicles in India.

What are flex fuel vehicles?

Flex fuel Vehicle

Flex fuel vehicles are interesting and environment-friendly if nothing. These vehicles are like regular petrol vehicles, but they operate on a blend of ethanol and petrol. Since the blending ratio is flexible in a pre-defined range, they are called flex fuel. Also, the source of obtaining ethanol remains flexible as well. Typically the blending ratios range from E10 (10% ethanol and 90% gasoline) to E85 (85% ethanol and 15% gasoline). 

It is because of this adaptability to various ethanol-gasoline mixtures that flex fuel vehicles are an eco-friendly alternative and a promising alternative.

How do flex fuel vehicles work?

Flex fuel vehicles aren’t a complicated engineering marvel, but they are certainly an admirable innovation. Flex fuel vehicles operate by putting to use conventional internal combustion engines, with some tweaks to adapt to the varied range of ethanol blends in the fuel. The engine is fitted with specially designed engines, sensors, and fuel delivery systems that can automatically adjust to the ethanol content in the fuel being used. This complex system detects the ethanol-gasoline ratio whenever a vehicle is filled with flex fuel and makes real-time adjustments to optimise combustion. 

This technology ensures that the vehicle performs efficiently regardless of the fuel blend, thus offering maximum operating efficiency and cleaner emissions.

Also Read :15 Tips to Increase Car Mileage : Fuel Efficiency Hacks

Benefits of flex fuel vehicles

1. Reduced carbon emissions

One of the most significant advantages of flex fuel vehicles is their potential to reduce carbon emissions, along with NOx and SOx content in exhaust gas.

2. Energy security

Ethanol production often occurs domestically and reduces our dependency on foreign oil imports to some extent. This enhances energy security by promoting the use of locally sourced, renewable resources.

3. Economic benefits

Ethanol production generates economic opportunities for farmers and the agricultural sector as multiple crops like Jatropha, sugarcane, and switchgrass are used to produce ethanol.

Also Read :Most Fuel-Efficient Cars in India

Drawbacks of flex fuel vehicles

While flex fuel vehicles offer numerous benefits, there are some drawbacks in their applications. These include:

1. Reduced fuel efficiency and peak power

When running on high ethanol blends, a flex fuel engine tends to experience a decrease in fuel efficiency in conjunction with a slight decrease in its peak power output. After all, ethanol blend has a lower calorific value in comparison to petrol. These engines are also more expensive to maintain due to ethanol’s corrosive nature.

2. Availability

Currently, ethanol blending stations are limited. Also, ethanol production is limited to a small scale in the Indian market, since the technology is still in its development stage.

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Components of a flex fuel vehicle

Key components in a flex fuel vehicle include the engine control module (ECM), fuel injectors, oxygen sensors, and a flex fuel sensor. These components work together to monitor and adjust the engine's performance based on the ethanol-gasoline ratio.

Challenges faced in flex fuel vehicles

While flex fuel vehicles offer a promising path towards sustainability, some challenges must be addressed. These include the need for further infrastructure development to support ethanol blending and research to enhance fuel efficiency and emissions control in FFVs. 

It is also important to reduce the initial production and ownership costs of such vehicles while spreading awareness about such vehicles, which may also contribute to a faster adoption rate. 

Future of flex fuel vehicles in India

India, like many other nations, is showing a growing interest in adopting flex fuel vehicles. The Indian government has set ambitious targets to reduce carbon emissions and promote sustainability in the transportation sector. The introduction of flex fuel vehicles aligns with these goals by offering an eco-friendly and domestically-sourced fuel option.

Upcoming flex fuel cars in India

1. Maruti Suzuki WagonR flex fuel

The Maruti Suzuki WagonR flex fuel prototype was showcased at the 2023 Bharat Mobility Expo. The prototype gives a picture of what lies in the future when Maruti Suzuki is planning to make its complete model line-up flex fuel ready by 2025. The carmaker claims the flex fuel WagonR boasts 79 per cent lower carbon emissions. Also, the prototype can run on any blend between E20 and E85.

2. Mahindra XUV300 flex fuel prototype

At the Bharat Mobility Expo, Mahindra also showcased its XUV300 flex fuel prototype, which can operate on a blend ratio of anywhere between 20 per cent to 85 per cent ethanol. The company revealed that the Mahindra XUV300 flex fuel engine produces a peak power output of 109 bhp and 200 Nm of max torque. The new-age flex fuel engines from Mahindra will make it to the market by 2025.

3. Toyota Innova Hycross flex fuel

Toyota is also piloting a project on flex fuel engines, and it recently showcased the Toyota Innova Hycross that can operate on up to E85 blends. The 2.0L petrol engine of the Innova Hycros hybrid was utilised to showcase the possibility of using ethanol-rich blends for reduced carbon emissions.

4. E20 flex fuel Cars

A host of carmakers have announced that their offerings can run on E20 blends. However, multiple complaints from consumers have surfaced on the internet about dull performance post the use of E20 petrol. Addressing the complaints, carmakers have advised owners to use unblended petrol or E10 blends. Maruti Suzuki, Toyota and more have made their cars E20-compliant.


In conclusion, while flex fuel vehicles represent a promising option for a greener and more sustainable future in the automotive industry, we still have several concerns to address in the near future, including the infrastructural support and incentives. 

With the Indian government's support and the development of ethanol infrastructure, flex fuel vehicles could play a pivotal role in reducing carbon emissions, boosting energy security, and offering consumers more eco-friendly choices. 

As India advances in its journey towards sustainability, flex fuel vehicles, or flex cars, may well become a significant player in the nation's efforts to build a cleaner, more environmentally responsible future.


Q. Is flex fuel good or bad for a car?

Flex fuel is generally good for a flex fuel car as it provides fuel flexibility and can be environmentally friendly, but it may slightly reduce fuel efficiency when compared to conventional fuel.

Q. Is flex fuel cheaper than petrol?

Flex fuel can be cheaper than petrol, but it depends on the region and current fuel prices.

Q. Is flex fuel available in India?

Yes, flex fuel is gradually becoming available in India, and its availability is expected to increase over time.

Q. What is the average cost of a flex fuel car in India?

We are yet to get official prices of the upcoming flex fuel cars in India.

Q. When can we expect flex fuel cars to launch in India?

Flex fuel cars will soon launch in India and several automakers are gearing up to launch flex fuel cars soon.

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