Power-shifting (also known as full-throttle shifting, flat-shifting or speed shifting) is a method of shifting used with manual transmissions to reduce the time where the driving wheels are not powered. Unlike a normal gear change, in a power shift the driver does not let off the accelerator. The clutch is briefly depressed while the shift lever is rapidly shifted into a higher gear, keeping the engine in its power band. This helps the car accelerate faster, but increases wear on and reduces the life expectancy of the clutch and the transmission beyond normal levels; flat-shifting may also increase fuel consumption. In most cases, there is a method of cutting the ignition and/or fuel delivery, in a similar fashion to a rev-limiter, which prevents the engine from over-revving when the load from the transmission is removed. Many aftermarket engine management systems provide this functionality as either a standard feature or as an option, usually combined with launch control.