What is Overdrive?

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   ThompsonPenposted 10 years ago

   What is Overdrive?
   
   Coming from the standpoint of someone who was raised on manual transmission, I don't understand what the Over Drive function is on a car. I hear it's to save gas, but then shouldn't we just drive in overdrive all the time? When do we put the car into it? I don't get it!

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2. 0

   JThomp42posted 10 years ago

   An overdrive (OD) is a mechanism that allows an automobile to cruise at sustained speed with reduced engine RPM, leading to better fuel economy.

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      ThompsonPenposted 10 years agoin reply to this

      I thought that was cruise control?

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      JThomp42posted 10 years agoin reply to this

      No, that is overdrive.

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3. 60

   BobMongerposted 10 years ago

   Overdrive is simply a higher gear one can engage after the top gear in your transmission has "maxed out" once highway speeds are reached. Trying to drive with OD engaged at lower speeds will not allow your engine to turn over fast enough to keep it running.  Some cars, instead of having an overdrive, have gone to a 5 speed transmission.

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4. 85

   Billie Kelpinposted 10 years ago

   when you go right past the exit where you were supposed to turn

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      ThompsonPenposted 10 years agoin reply to this

      True that!

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5. 75

   alancaster149posted 10 years ago

   Onceover - in the UK at least, gearboxes might have been different in the US/elsewhere - we had four speed gearboxes. The average speed you could reach safely without taxing the gearbox and gulping down your precious fuel was around 50mph. To achieve greater speeds and longer running - on motorways and A-road designated highways - overdrive was introduced. Aside from reducing fuel consumption it 'quietened' the engine at speed. I had it in my first three Land Rovers, and on my third - when the Perkins diesel engine packed up - a 2500 Tdi Land Rover engine was installed. With its higher torque the Tdi 'went through the older gearbox like a hot knife through butter'. For a while after my gearbox was given a 'recon' job it sounded like I was driving a tank or railway engine! To combat this being repeated, a five-speed Land Rover gearbox was installed. The engine noise went down straight off and fuel consumption went down with it.
   Hey presto!

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6. 56

   Caveman67posted 10 years ago

   Overdrive as the name suggests is like having one or multiple more wheel rotations at a specific engine speed. In simple language it helps the engine run at lower rpm(lower revolutions per minute) and helps you save the fuel.
   
   When the system was put into production, then at that point of time overdrive had to be selected manually with independent lever. This was because of the relatively poor engine power. One can select overdrive only after hitting the highway and once he/she had build up enough speed.
   As the technology changed overdrive came fitted in the gearboxes. Now the technology is so advanced that overdrive is selected electronically. The sensors detect the need for overdrive and even before you come to know overdrive would have been selected. You dont even feel. Now thats technology

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