Editing Automatic transmission (section)

====Other positions and modes====
[[File:Aero Star MP37F Allison Shift selector and Parking brake lever.jpg|thumb|right|Push-button gear selector in a 2010–2014 [[Mitsubishi Fuso Aero Star]] bus]]
Many transmissions also include positions to restrict the gear selection to the lower gears and engages the [[engine braking|engine brake]]. These positions are often labelled "L" (low gear), "S" (second gear) or the number of the highest gear used in that position (eg 3, 2 or 1). If these positions are engaged at a time when it would result in excessive engine speed, many modern transmissions disregard the selector position and remain in the higher gear.

In descending order of the highest gear available:
* '''3''': Restricts the transmission to the lowest three gear ratios. In a 4-speed automatic transmission, this is often used to prevent the car shifting into the [[overdrive (mechanics)|overdrive]] ratio. In some cars,{{which|date=November 2020}} the position labelled "D" performs this function, while another position labelled "OD" or a boxed "[D]" allows all gears to be used.
* '''2''' (also labelled "S"): Restricts the transmission to the lowest two gear ratios. In some cars, it is also used to accelerate from standstill in 2nd gear instead of 1st, for situations of reduced traction (such as snow or gravel). This function is sometimes called "winter mode", labelled "W".
* '''1''' (also labelled "L"): Restricts the transmission to 1st gear only, also known as a "low gear". This is useful when a large torque is required at the wheels (for example, when accelerating up a steep incline); however use at higher speeds can run the engine at an excessive speed, risking overheating or damage.

Many modern transmissions include modes to adjust the shift logic to prefer either [[Engine power|power]] or [[Fuel economy in automobiles|fuel economy]]. "Sport" (also called "Power" or "Performance") modes cause gear shifts to occur at higher engine speeds, allowing higher acceleration. "Economy" (also called "Eco" or "Comfort") modes cause gear shifts to occur at lower engine speeds to reduce fuel consumption.