Sept. 25, 2022

India’s first ‘flex fuel’ car, a Toyota sedan that can run on one or multiple fuel types and developed as part of a new pilot aimed at deleveraging the country’s dependence on imported fossil fuels for transportation, is set for an unveiling later this month.


  • A flex fuel, or flexible fuel, vehicle has an internal combustion engine (ICE), but unlike a regular petrol or diesel vehicle, this can run on more than one type of fuel, or even a mixture of fuels.
  • The most common versions use a blend of petrol and ethanol or methanol, but these engines are also equipped to run on 100 per cent petrol or ethanol as well.
  • This is made possible by equipping the engine with a fuel mix sensor and an engine control module (ECM) programming that senses and automatically adjusts for any ratio of designated fuels.

Pros and cons

  • The most important benefit is that the use of ethanol blending sharply lowers harmful pollutants such as carbon monoxide, sulphur, and carbon and nitrogen oxides. Another obvious benefit is that blending will help cutback on oil imports for fueling vehicles.
  • But there are problems: a flex fuel car typically takes a small hit on fuel efficiency when using ethanol for motive power, ranging from between 4 per cent and 8 per cent.
  • So, while fuel economy is generally lower with increased levels of ethanol (engines are optimised for petrol), on the flip side, many flex fuel vehicles have improved acceleration performance when operating on higher ethanol blends.