Effect of biodiesel and ethanol on load limits of high-efficiency premixed low-temperature combustion in a diesel engine

► The effect of biodiesel and ethanol on low temperature combustion (LTC) load limits are investigated. ► LTC is smoke limited at high load for diesel and biodiesel fuels. ► Ultra low smoke emission is possible with biodiesel-ethanol fuel. ► The high load limits of biodiesel-ethanol LTC is caused by a drop of combustion efficiency rather than smoke. ► High-efficiency LTC load limits can be extended to 0.35-0.82 MPa IMEP with biodiesel-ethanol.