Toyota’s flex-fuel prototype: How it will work, what advantages it offers

• Recently, Toyota unveiled a prototype of the Innova Hycross with a flex-fuel hybrid powertrain claimed to be the world's first BS6 Stage II-compliant flex-fuel vehicle.

Hycross Prototype

• It has an Atkinson Cycle petrol engine coupled with an electric motor, the same as in the hybrid version of the standard Hycross.
• It can run on petrol with more than 20% ethanol blending, currently mandated in India.
• Also, its performance would be at par with the standard Hycross hybrid, even with ethanol-blended petrol.
• It would run 60% of the time in the electric vehicle mode using energy stored in the battery pack.
• It will achieve low carbon emissions “on a comprehensive well-to-wheel basis”

Flex-fuel Technology

• A flex-fuel vehicle typically has an internal combustion engine (ICE).
• However, unlike a regular petrol vehicle, it can run on more than one type of fuel, or a mixture of these fuels.
• The most common versions use a blend of petrol and ethanol or methanol. Flex-fuel vehicles such as the prototype Hycross can run on blends of ethanol that are far higher than the current standard 20% mix (E20).
• The flex engine push is part of the broader strategy to cut dependence on imported crude in the medium-to-long run.

Functioning of Flex Fuel Engine

• Most components in a flex fuel vehicle are the same as those in petrol-based cars.
• However, certain modifications are made to the fuel pump and fuel injection system.
• This is done to adjust to the different chemical properties and energy content in ethanol/ methanol.
• The engine control module (ECM) is also calibrated to accommodate the higher oxygen content of ethanol.

Flex Pros

• The use of ethanol blending sharply lowers harmful pollutants such as carbon monoxide, sulphur, and carbon and nitrogen oxides
• The blending will help cut back on oil imports to fuel vehicles.
  • The expected implementation of E20 by April 2025 is estimated to result in annual savings of Rs 35,000 crore in India’s oil import bill.
• They have improved acceleration performance when operating on higher ethanol blends.
• Alternative fuels contribute towards economical and sustainable mobility.

Flex Cons

• They typically take a 4-8% hit on fuel efficiency when using ethanol for motive power.
• Source crops such as sugarcane are usually very water-intensive.
  • NITI Aayog report, 2019-200: More than 90% of the ethanol produced in the country came from sugarcane.
• There is a need for flexibility of fuel mix to cope up with adverse situations.
• There is also a need for government subsidy to narrow the price gap of higher ethanol blends, in order to make the proposition viable.

Conclusion

• To overcome the challenges of lower fuel efficiency of flex-fuel vehicles, electrified flex-fuel vehicles are being introduced.
• This offers the advantages of both a flex-fuel engine and an electric powertrain, as in the case with the Hycross prototype.