Why Do Trucks Start In Second Gear? - Vol.94
The engine size and the overall size of an automobile define the number of gears in the transmission. The type of vehicle also defines the number of gears as well. There is often a difference in the number of gears if the transmission is automatic or manual. Manual transmissions have been seen to have more gears than automatic transmissions.
Especially for manual transmissions, the driver needs to know exactly when to switch between what gear. The typical reverse gear is present in all automobiles. Apart from the reverse there are forward gears that vary with the engine size and transmission type. For typical sedans there may be four or five gears for the forward motion. These are called 4-speed or 5-speed manual transmissions. Sports cars tend to have more gears. They can go up to 6-speed or 7-speed transmissions. For larger utility vehicles like trucks the transmission can be 8-speed as well and might even have more than one reverse gear option.
The amount of power that the engine has and the torque that it can produce defines the number of gears. For larger vehicles like trucks, the engines are huge and can produce a massive amount of torque and acceleration. Their clutch and brake are stiffer as well. This is why driving such large vehicles is not an easy task.
For manual transmissions, each gear number has a different range and specific fuel distribution. The gear ratio differs with the engine and the number of gears as well. A normal manual sedan is usually started in the first gear and allowed to progress to a certain speed and then shifted to 2nd gear and the third and so on. It is advised not to drive in one gear for too long and also not to drive in lower gears for too long. As the speed of the car increases the gears have to be switched to one above. In case of a normal sedan it is said that starting in the second or third gear creates pressure on the clutch plate and cable and damages the pressure plates as well. Hence, for best performance the car needs to start in first gear.
However, this is not the case for large vehicles. Utility vehicles like trucks in particular have huge engines. These engines produce massive torque and acceleration. Starting a truck in first gear is often avoided by truckers. The basic reason is the loss of control. If a truck starts in first gear it achieves higher speeds more easily because of a higher fuel distribution in first gear and also other gear mechanics. It becomes difficult to control the truck in first gear and there is a chance that the driver might lose control and spin the truck. A spinning truck is very dangerous as it can crash into anything and topple over as well.
It is advised that trucks be started in second gear so that the shoot-up effect of the truck is reduced and take off is slower and more controllable. The speed rises slowly and the truck remains more stable. The basic motive is to avoid the wilder take off and difficult braking motion. Obviously, a vehicle that size is not easy to come to a complete halt. Hence, the second gear stabilizes the truck's motion and allows the driver to accelerate gently and smoothly.
This is quite a commonly used technique by truck drivers all over the world. Any large vehicle should not be allowed to start off with a speedy start because their design does not allow them to accelerate so quickly to high speeds.