The increase of intake air temperature enlarges the difference of peak pressure cylinder-to-cylinder, and the difference is mainly caused by 1# and 4# cylinder. In the meantime, the COVpp of each cylinder decreases with the increase of inlet air temperature. The UED increases gradually with the increase of intake air temperature, but the UED is usually lower than 8% at various intake air temperatures when MSP is less than 40%. It suggests the inlet air temperature in the range of 35–80 C is proper when MSP less than 40%.