It is anticipated that worldwide energy demand will approximately double by 2050, whilst at the same time, CO2 emissions need to be halved. Therefore, there is increasing pressure to improve the efficiency of all machines, with great focus on improving the fuel efficiency of passenger cars. The use of downsized, boosted, gasoline engines, can lead to exceptional fuel economy, and on a well-to-wheels basis, can give similar CO2 emissions to electric vehicles (depending, of course, on how the electricity is generated).
In this paper, the development of a low weight concept car is reported. The car is equipped with a three-cylinder 0.66 litre gasoline engine, and has achieved over 100 miles per imperial gallon, in real world driving conditions. The use of low viscosity synthetic engine and transmission lubricants contributed to this exceptional fuel economy, and data is presented showing how the measured fired friction mean effective pressure (FMEP) of the engine varied with the type of oil that lubricated it. In addition, there is discussion of the modifications that were made to the engine to enable the exceptional fuel economy performance of this vehicle.