when do you use overdrive on a truck
Overdrive (mechanics) Generally speaking, overdrive is the highest gear in the transmission. Overdrive allows the engine to operate at a lower RPM for a given road speed. This allows the vehicle to achieve better fuel efficiency, and often quieter operation on the highway. When it is switched on, an automatic transmission can shift into overdrive mode after a certain speed is reached (usually 70+ km/h [40-45 mph or more] depending on the load). When it is off, the automatic transmission shifting is limited to the lower gears. Overdrive should usually be selected when the average speed is above 70 km/h (40-45 mph).
Defensive driving The standard Safe Practices for Motor Vehicle Operations, ANSI/ASSE Z15.1, defines defensive driving skills as "driving to save lives, time, and money, in spite of the conditions around you and the actions of others."[1] This definition is taken from the National Safety Council's Defensive Driving Course. It is a form of training for motor vehicle drivers that goes beyond mastery of the rules of the road and the basic mechanics of driving. Its aim is to reduce the risk of collision by anticipating dangerous situations, despite adverse conditions or the mistakes of others. This can be achieved through adherence to a variety of general guidelines, such as following the assured clear distance ahead and two second rules, as well as the practice of specific driving techniques.