Fuel Efficiency Technology

Technologies behind enhancing fuel efficiency of a car. 



Fuel efficiency is one of the most crucial aspects of an automobile. More so in a country obsessed (so aptly demonstrated in Maruti Suzuki’s corporate ads) with fuel efficiencies figures. Even a super premium luxury Indian car buyer is interested in knowing the fuel efficiency figures of his car.

A drop dead gorgeous looking car with splendid performance, great ride and handling will lose all its sheen and meaning to a new car buyer in India if its efficiency figures are a suspect, such cars are ignored by most Indian new car buyers.

Fuel efficiency today is probably the most important question  for all new car buyers in India, all thanks to stratospheric rise in gasoline (petrol) prices in India. The real reason to seek and buy alternate fuel cars in India is not their love for the environment but a love for their pockets. A car whose fuel efficiency figures dents their pockets the least, seems to have the greatest buy reason in their mind. Thanks to Indian new car buyers obsession with fuel efficiency, alternative fuel vehicles are becoming part of today’s mobility in India.


Efficiency can be defined as the ratio of output work to input energy. If we multiply this result by 100, it will give us efficiency figures in percentage terms. Mathematically efficiency can be represented as:

Efficiency = (Output/ Input) * 100

Fuel efficiency is one form of thermal efficiency; its efficiency is dependent on how efficiently the conversion process that converts chemical energy of a fuel into kinetic energy or useful work done. So in case of automobiles, fuel efficiency figures represents how effectively the chemical energy of fuel used is converted into kinetic energy or work done. This in case of cars or vehicles, is the measure of the distance travelled per unit of fuel used. It’s mandatory for each car manufacturer to announce the fuel efficiency figures for each of their models.


Units of fuel efficiency are different in different parts of the world. For example while U.S. & U.K. have miles per gallon (mpg) as efficiency unit, South Asian countries use km per liter to denote the average numbers. Following conversion units will be helpful to convert the various units into other figures.

1 Gallon 3.78 Litres 
1 Mile 1.6 Km

Take, for example, Civic Hybrid Fuel Efficiency of 42 mpg is the same as 17.78 Km/L (42* 1.6 / 3.78 liter = 17.78 km/l).


Represents reciprocal of fuel efficiency & is calculated in terms of fuel consumed in liters for covering 100 km. Therefore if your car comes with fuel efficiency figure of 20 km/l that means it would drive 20 km in 1 liter. So for travelling 100 km, it takes 5 liter of fuel; therefore its fuel consumption figure is 5 liter/ 100 km. 


Its believed that out of every unit of fuel only 25% of is converted into useful efficiency (work done) rest is lost due to friction, exhaust & coolant losses.  

PREMIXED COMPRESSION CHARGE COMPRESSION IGNITION (PCCI): Premixed charge compression ignition is the new technology being developed by Cummins & its team. 

DIESEL COMPRESSED AIR HYBRID: This technology promises an efficiency increase of 15% over current generation of diesel power plants. If achieved  this would lead to the diesel engine delivering nearly 50 %, which will be a remarkable improvement. 

STOICHIOMETRIC COMPRESSION-IGNITION: This technology will use the combined improvements achieved by low pressure loop cooled exhaust system with three-way catalyst. This results in lowering the overall peak operating temperature range. 

HOMOGENEOUS CHARGE OMPRESSION IGNITION:  This technology relies very heavily on the very well mixed charge-air combination, which is lean in nature & ignites itself. Thus very spontaneous release of the energy with almost no lag helps to do the work in most efficient manner. 

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