One obvious method to reduce the fuel consumption of internal combustion engines is to reduce the energy losses.
Losses like moving large pistons, pumping a minimal amount of air inside the cilinder: which is just the average status if a large engine is delevering a low amount of power (idling, city use, low speeds).
The trend in all cars is to reduce the cilinder size and increase the amount of air you can push inside the engine with a turbo so you can get the same amount of maximum power. It reduces the fuel consumption, but with a price: the bigger the turbo the bigger the delay in response. The dreaded “turbo-lag” translates to a negative driving experience and potentially unsafe situations.
Researchers in Switzerland experiment with a novel solution to the problem. If the engine can function as an air pump when you are braking you can store air in a pressure tank. If you want to accelerate again and the turbo is lagging, pressurized air is used to fill the gap.
Smart engineering.
However: you wonder if this added complexity will ever be able to compete with serial hybrids where combustion engines mainly function as generators: fundamentally no problem with a turbo-lag.
Source : Greencarcongress
