The researchers studied how adding extra air pressure to a special type of engine can improve its efficiency. They used a 2.0 L engine that runs on a specific type of fuel and tested it at different air pressures and loads. They found that increasing the air pressure can make the engine work better, with higher efficiency and improved combustion. By adjusting the air pressure and fuel mixture, they were able to make the engine run more smoothly and produce more power. This shows that with the right adjustments, this type of engine can work well even with lower compression ratios.