The primary difference between automatic and manual transmissions is with the forward gears, as both transmissions require manual shifting into reverse and neutral. With an automatic, the driver shifts into "drive," and the car does the rest of the work. A manual transmission requires the driver to manually shift between the forward gears, and also to use a clutch to disengage the engine from the transmission during shifting. Automatics also have a "park" option.
Manual shifting in an automatic transmission vehicle only involves moving a gear shifter to the desired setting, while a manual transmission requires shifting during acceleration and deceleration, and has the added requirement of using a clutch pedal.
Manual transmission vehicles commonly have four or five forward gears to choose from, with the fifth gear designed for cruising speed. Automatic transmissions are configured similarly, but the driver does not need change gears manually.
Most manual transmission vehicles have a tachometer next to the speedometer. The "tach" shows the engine's revolutions per minute, and indicate how hard the engine is working. That can provide information about when a driver should shift gears. Automatic transmission vehicles sometimes have tachometers, although there's not much the driver can do with the information.
A new car with a manual transmission costs about $1,000 less than an automatic, as can be seen by comparing options for vehicles at Ford, Toyota and General Motors dealerships, and others. Not all models have both transmissions as options.
According to the U.S. Environmental Protection Agency, manual transmissions usually provide better gas mileage -- about a mile or two per gallon more than automatics, mainly on the highway.
Despite the cost advantages of manual transmissions, the vast majority of drivers prefer automatics for their ease of use, particularly in city driving with frequent stops and starts. Manual transmissions also are more difficult to learn to use.
