Nissan is developing an engine for road vehicles that could achieve 50% thermal efficiency, which means the potential for much more fuel-efficient vehicles.
An engine’s thermal efficiency is a measure of how much of the thermal energy generated by combustion is actually converted into useful work. A good rating for a street car is around 40%, while 50% is a rating that is usually associated with it the best Formula 1 engines.
Nissan said Friday that an engine for road vehicles could achieve 50% thermal efficiency, but there’s a catch: the engine would have to run at a constant speed, such as when used as a generator in an extended-range electric vehicle.
In a conventional automobile, an engine experiences a variety of speeds and loads, which prevents it from running in its most optimal condition due to the rich air-fuel mixture required at certain speeds. This is not the case with an engine that acts as a generator and can continuously run at a level that allows for a lean air-fuel mixture.
However, Nissan plans to further improve the efficiency of an engine that is running in a steady state by optimizing cylinder gas flow (the flow of air-fuel mixture drawn into the cylinder) and ignition, thereby reducing the Engine will be able to reliably burn an even leaner air-fuel mixture at a higher compression ratio. By adding thermal energy recovery systems, Nissan has managed to achieve 50% thermal efficiency.
Such a motor could be used in one of Nissan’s E-Power models. Nissan’s E-Power models are essentially electric vehicles with batteries that are charged while on the move using a combination of energy recovery and a small motor that only serves as a generator. Electricity generated by the engine can be sent directly to the vehicle’s electric motors even in heavy load situations.
That was the first E-Power model Nissan Note E-Power The subcompact hatchback was launched in January 2016. More to come, including Nissan’s premium brand Infiniti. However, Nissan hasn’t said when we’ll see one with 50% thermal efficiency.