The UED gradually increases with the increase of intake air temperature, and it is usually less
than 8% when intake air temperatures lower than 80 C under 40% MSP. It suggests it is helpful to
decrease the UED when the intake air temperature is in the range of 35–80 C as MSP less than 40%. In
addition, the difference of pressure between cylinder-to-cylinder decreases with the increase of engine
speed, it can be considered raising MSP at high engine speed in order to gain better engine economy.