Most semi-trucks have nine to thirteen gears. This is usually the standard number of shifts found in the majority of commercial trucks.
A tractor-trailer can have nine, ten, eleven, twelve or thirteen gears; it depends on the model and year of the truck. Some older models may feature fewer gears, while newer models may feature more.
Generally speaking, a nine-speed semi-truck will have one gear for each speed from first (1) to ninth (9). A ten-speed has two additional gears that are located in between each of the nine main speeds.
An eleven-speed has three additional gears that are located in between each of the nine main speeds. Twelve and thirteen speed trucks will have four and five additional shift points respectively.
Each gear is designed to take advantage of different engine RPMs and torque outputs. The lower gears are designed for starting off and climbing hills with heavy loads, while higher gears are used for cruising down highways at high speed with lighter loads. Most truck drivers use a combination of lower and higher gears depending on road conditions.
In addition to having different numbers of shift points, semi-trucks also feature either manual or automatic transmissions. Manual transmissions require drivers to use a clutch pedal when shifting between gears, while automatic transmissions do not require any input from the driver other than selecting which gear they want to be in.
Conclusion:
The number of shifts on a semi truck varies depending on its model and year. Generally speaking, most commercial trucks have nine to thirteen different shift points.
They also come with either manual or automatic transmissions depending on preference. Knowing how many shifts a semi truck has allows drivers to make better use of their vehicles’ engine power when driving on different road conditions.
