This may be a rookie question but what is overdrive? What are the affects of it being on or off in the zx auto? Always wondered? Cheers guys

its your 4th Gear on the auto box

I've never understood why you would want to turn it off

I think but not sure, holds in gears a bit longer, acceleration seems better, or maybe my imagination ! Lol

I've never understood why you would want to turn it off

 

It has a tendency to go into overdrive around town when it's not always required.

 

It's a good thing though, just another element of control. Who needs a manual?! :lol:

Why do older manuals (MG's etc) have an overdrive?

when Auto boxs came on the market they was only 2 speed .. but then the demand on better control and economy needed a 3rd gear and so on as the gears went on

till now with modern cars having 5>6speed autos think they ditched the ( overdrive button )

 

Auto

1st is under drive

2nd is under drive

3rd is Direct Drive Ratio

4th is Over drive ratio

 

Manual

1st under drive

2nd under drive

3rd under drive

4th Under drive ( 5sp box its a Direct drive )

5th Direct drive ( 5sp box its a Over drive )

6th Over drive

 

this is normally how close Most gear boxs are in to out ratio

'Overdrive' is simply any gear with a ratio less than 1:1, i.e. where the driveshafts rotate at a higher speed than the engine.

 

Edit: Beaten to it :D

Edited January 10, 201312 yr by Noz

cheers guys that makes sense now

It gives your Zed another weapon to try and kill you with. Mine likes to change out of overdrive when it feels like it, normally just as it starts to rain

It gives your Zed another weapon to try and kill you with. Mine likes to change out of overdrive when it feels like it, normally just as it starts to rain

 

Lol great answer mate:clap:

people get confused when they hear the T/C locking up on these auto,s and think its an extra gear when in actual fact its just forming a direct drive from the crank to the prop...Does sound nice thou when your feathering the throttle and it locks then you nail it:cool3:

Thanks lads, I understand it now :)

overdrive makes the car drive like crap round town when its on, taking it off on a roads turns it into an animal and turning it on on the motorway turn it into a lovely lazy cruiser.

I've never understood why you would want to turn it off

 

For the same reason you might want to put the selector in "1" or "2" - all you are doing is limiting the highest gear you want the car to shift into. For example, if you want to increase engine braking on a long down-hill stretch; or if you want to maintain engine response driving around a twisty up-hill road (like the Hardknott Pass in the Lake District - LOL). In a manual you would most likely not shift higher than 2nd or 3rd - so switching off the o/d or selecting "2" will keep your auto in said lower gears

 

Why do older manuals (MG's etc) have an overdrive?

 

Mark and Noz have explained what the OD is - and back in the olden days such cars like the MG (and my old 1961 Rover 100) only had 4 gears. 5th gear on a manual was something of a luxury on all but the high performance cars until well into the 1980s!! So adding the overdrive gave the effect of a higher gear for cruising; reducing engine effort, noise and improving economy.

 

Whilst it was a manual, my old Rover had a kickdown switch under the accelerator, to turn off the OD momentarily when acceleration was required....... if you could call it acceleration in poor old "Auntie!"

 

Richard:cool3: