<P> 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 ) . </P>
<P> 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 ) . </P>
when do you use overdrive on a truck
when do you use overdrive on a truck
when the average speed is above 70 km / h ( 40 - 45 mph )
when the average speed is above 70 km / h ( 40 - 45 mph )