A system for an engine of a vehicle, comprising of a cylinder located in the engine, a delivery system configured to deliver fuel and a fluid to at least an engine cylinder while the vehicle is traveling, said fluid comprising alcohol and/or water, and a control system for varying an amount of said fuel and fluid delivered to the cylinder in different ratios as a condition varies, said controller further varying a spark timing of a spark in said cylinder as an amount of alcohol and/or water in said fluid varies.