The pressure difference cylinder-to-cylinder and the UED increases gradually with the increase of MSP under various
engine load. The COVpp increases with MSP under low engine load, and the COVpp curves vary very little under low MSP under 75% and 100% engine load, and a significantly rise appeared when MSP further increases. In the DMDF engine, the imbalance of methanol entered into each cylinder is one of the main reason that causes pressure unevenness of 4 cylinders.