What is Over Drive?

Question

I just got a Nissan Versa 08 and it is the first car I have ever had. I don't know if I'm supposed to drive with overdrive on or off? or what the heck it is for that matter? Tasukatte!

Answer 1

If you were to open up the glove box of your new car and look around a bit, you will find an amazing little book called an 'Owner's Manual' that provides you with the answers to dozens of questions you may have about your new car.  Take a few moments to read through your manual, and you will find information on how to operate and maintain your new car to keep it in good working condition for many years to come.

Answer 2

Generally speaking, overdrive (OD) is the highest gear in the transmission. Most automatic transmissions have three speeds and overdrive (fourth speed). Overdrive allows the engine to operate at a lower rpm for a given road speed. This allows the vehicle to realize better fuel efficiency, and often quieter operation on the highway. When it is switched on, the transmission can shift into overdrive mode after a certain speed is reached (usually 70+ km/h [45+ mph] depending on the load). When it is off, the transmission shifting is limited to the lower gears. For normal driving conditions, operation of the overdrive should be enabled only if the average speed is above 70 km/h (approx. 43 MPH).

It may be necessary to switch it off if the vehicle is being operated in a mountainous area.

The automatic transmission automatically shifts from OD to third gear when more load is present. When less load is present, it shifts back to OD. Under certain conditions, for example driving uphill or towing a trailer, the transmission may "hunt" between OD and the third gear, shifting back and forth. In this case, switching it off can help the transmission to 'decide'. It may also be advantageous to switch it off if engine braking is desired, for example when driving downhill. The vehicle's owner's manual has information and procedures regarding such situations.

The overdrive consists of an electrically or hydraulically operated epicyclic gear train bolted behind the transmission unit. It can either couple the input driveshaft directly to the output shaft (or propeller shaft) (1:1), or increase the output speed so that it turns faster than the input shaft (1:1 + n). Thus the output shaft may be "overdriven" relative to the input shaft. In newer transmissions, the overdrive speed(s) are typically as a result of combinations of planetary/epicyclic gearsets which are integrated in the transmission. In these cases, there is no separately identifiable "overdrive" unit. A number of such transmissions and transaxles are manufactured by Aisin, for use in vehicles produced by many different manufacturers. In older vehicles, it is sometimes actuated by a k**b or button, often incorporated into the gearshift k**b, and does not require operation of the clutch. Newer vehicles have electronic overdrive in which the computer automatically adjusts to the conditions of power need and load.

Answer 3

the engine to transmission ratio

most vehicles in top gear there's only a 1:1 ratio

overdrive is another gear beyond that

Answer 4

When you put it in overdive the engine will run at a lower rpm.  Making it cooler, and giving you better gas milage.  Use overdive unless you are pulling a trailer.

Answer 5

if ya dont know et a better sales person next time.

Answer 6

Overdrive is like the highest gear your transmission has -

best used on the highway - or for extended periods at 45 mph and above

if you are in city - stop and go - 30-35-40 range

I would select the highest gear under overdrive (3) maybe

the more your car shifts, it uses more fuel

BUT when you get on the highway - slip the OverDrive

on and gets the best gas mileage you car can offer

ps : also check your tires to make sure they have the proper

# of pounds of air - usually 32 (but we had a rental car that took 35)

and that your air filters are clean!

have a great 2008!

Answer 7

Generally speaking, overdrive (OD) is the highest gear in the transmission. Most automatic transmissions have three speeds and overdrive (fourth speed). Overdrive allows the engine to operate at a lower rpm for a given road speed. This allows the vehicle to realize better fuel efficiency, and often quieter operation on the highway. When it is switched on, the transmission can shift into overdrive mode after a certain speed is reached (usually 70+ km/h [45+ mph] depending on the load). When it is off, the transmission shifting is limited to the lower gears. For normal driving conditions, operation of the overdrive should be enabled only if the average speed is above 70 km/h (approx. 43 MPH).

It may be necessary to switch it off if the vehicle is being operated in a mountainous area.

The automatic transmission automatically shifts from OD to third gear when more load is present. When less load is present, it shifts back to OD. Under certain conditions, for example driving uphill or towing a trailer, the transmission may "hunt" between OD and the third gear, shifting back and forth. In this case, switching it off can help the transmission to 'decide'. It may also be advantageous to switch it off if engine braking is desired, for example when driving downhill. The vehicle's owner's manual has information and procedures regarding such situations.

Answer 8

idk- if u wanna find a better answer i would change the subject to automotive.

Answer 9

What is the search feature on yahoo answers?  Seriously, someone asks this EVERY DAY.

It's a high gear for highway cruising.  Turn it off when you're going up hills.  That is all you need to know.

Answer 10

Congrats on your first car!

Without getting technical, essentially overdrive is an effcient high gear.  Under most circumstances you will want to drive with it on for the best fuel economy.  

The only time you'd really want to turn it off is for unusual road conditions or possibly towing.

Answer 11

Overdrive refers to the gear ratio. When you are in overdrive your wheels are turning faster than your transmission.

This means you are saving on gass but lose a lot on power. It is designed to be used for cruising on the highway and not for acceleration.