Neutral/No gear (N)– This disconnects the transmission from the wheels so the car can move freely under its own weight. This is the only other selection in which the car can be started.
Drive (D)– This allows the car to move forward and accelerate through its range of gears. The number of gears a transmission has depends on the model, but they can commonly range from 3 (predominant before the 1990's), 4, 5 (the most common), 6 (found in
VW/
Audi Direct Shift Gearbox), 7 (found in Mercedes 7G gearbox, BMW M5 and
VW/
Audi Direct Shift Gearbox) and 8 in the newer models of
Lexus cars. Some cars when put into D will automatically lock the doors or turn on the
Daytime Running Lamps.
OverDrive ([D], OD, or a boxed D) - This mode is used in some transmissions to allow early Computer Controlled Transmissions to engage the Automatic Overdrive. In these transmissions, Drive (D) locks the Automatic Overdrive off, but is identical otherwise. OD (Overdrive) in these cars is engaged under steady speeds or low acceleration at approximately 35-45 mph (approx. 72 km/h). Under hard acceleration or below 35-45 mph, the transmission will automatically downshift. Vehicles with this option should be driven in this mode unless circumstances require a lower gear.
Second (2 or S) –
This mode limits the transmission to the first two gears, or more commonly locks the transmission in second gear. This can be used to drive in adverse conditions such as
snow and ice, as well as climbing or going down hills in the winter time. Some vehicles will automatically upshift out of second gear in this mode if a certain rpm range is reached, to prevent engine damage.
First (1 or L) – This mode locks the transmission in first gear only. It will not accelerate through any gear range. This, like second, can be used during the winter season, or for towing.