Mitsubishi (when To Use Overdrive)

[KhunDtaa]

I own a Mitsubishi Strada L2000, disesel with 2 wheel drive automatic with overdrive. My question is when should I put it in overdrive seems to be like a lower gear.

[Cuban]

Overdrive is used when you are moving at higher speeds.

Turn overdrive off when driving around town and feel you need more response to pull away quickly at the traffic lights etc.

Unless you are a measuring your travel time in milliseconds it really does not make a huge differance in day to day driving. This is why the 'normal' setting is overdrive on, and the warning light indicates when you have turned it off.

HTH

[monty]

Overdrive is used when you are moving at higher speeds.

Turn overdrive off when driving around town and feel you need more response to pull away quickly at the traffic lights etc.

Unless you are a measuring your travel time in milliseconds it really does not make a huge differance in day to day driving. This is why the 'normal' setting is overdrive on, and the warning light indicates when you have turned it off.

HTH

Depending on the gearbox it might not be entirely true!

There are two overdrive systems in use, on one system overdrive is just the highest gear, and disabling the overdrive just stops the gearbox of going into the highest gear. I think this is the most used system, it works like that on a Nissan Cefiro and a Volvo I have.

Enabling or disabling the overdrive has no influence at all on the first 3 gears. I do have and economy/sport switch, which does influence the changing of all gears. Engine revs higher before switching a gear up, and kick down comes with not as much throttle needed...This is what I need to do to get away faster at red lights without having to floor the throttle!

Another system is where the overdrive is a complete separate gear behind the main gear box, this one would indeed influence all the gears.

I still remember some older manual gear cars having this overdrive, mostly actuated by a little switch on the gear lever.

Used to have fun driving around thinking I had an 8 gear car

1st without OD -> 1st with OD-> 2nd without OD -> 2nd with OD and so on...

[KhunDtaa]

Overdrive is used when you are moving at higher speeds.

Turn overdrive off when driving around town and feel you need more response to pull away quickly at the traffic lights etc.

Unless you are a measuring your travel time in milliseconds it really does not make a huge differance in day to day driving. This is why the 'normal' setting is overdrive on, and the warning light indicates when you have turned it off.

HTH

Depending on the gearbox it might not be entirely true!

There are two overdrive systems in use, on one system overdrive is just the highest gear, and disabling the overdrive just stops the gearbox of going into the highest gear. I think this is the most used system, it works like that on a Nissan Cefiro and a Volvo I have.

Enabling or disabling the overdrive has no influence at all on the first 3 gears. I do have and economy/sport switch, which does influence the changing of all gears. Engine revs higher before switching a gear up, and kick down comes with not as much throttle needed...This is what I need to do to get away faster at red lights without having to floor the throttle!

Another system is where the overdrive is a complete separate gear behind the main gear box, this one would indeed influence all the gears.

I still remember some older manual gear cars having this overdrive, mostly actuated by a little switch on the gear lever.

Used to have fun driving around thinking I had an 8 gear car

1st without OD -> 1st with OD-> 2nd without OD -> 2nd with OD and so on...

The overdrive in my car seems to be a lower gear feels almost as if I am putting it in low gear. This is why I am so confused when to use it if at all and what effect on fuel economy it has.

Edited May 24, 2008 by KhunDtaa

[wilko]

Overdrive is in essence a quick change gear after the gearbox that gears UP. When OFF the vehicle is in "direct drive". It can be available therefore on any gear but is usually disabled on lower gears. The main purpose is to reduce the engine revs when cruising....and so hopefully improve fuel consumption. As said above when switched "ON" your car is operating with higher ratios so things like acceleration may suffer a little....

[Plus]

RPMs will go up for the same speed, fuel consumption will go down but torque (and acceleration) at higher RPMs is usually better.

It's a fast way to rev up the engine for a quick overtake. In some cars OD it's even called "Power button".

In turbo diesels with flat torque curve the difference is less pronounced than in petrol cars that have torque peaks and saddles. I have no idea what effect does it have in OP's old Mitsu.

[wilko]

In "overdrive" - RPM go down, in direct drive they will go up to normal. The engine is rotating more slowly at the same speed and in theory will use less fuel.

[quiksilva]

I still remember some older manual gear cars having this overdrive, mostly actuated by a little switch on the gear lever.

Used to have fun driving around thinking I had an 8 gear car

1st without OD -> 1st with OD-> 2nd without OD -> 2nd with OD and so on...

Ahhh my 1972 MGBGT had that, great little car. Well it looked and sounded nice anyway

[philipm]

when to shift into overdrive? well when you are on your top gear, without overdrive activated, lets say the top rpm is 4200rpm, like the triton 3.2, i always change into overdrive between 2,500-3,200rpm, shifting between these rpms, it will retain maxium torque and best fuel efficency.

even when draging, dont attempt to rev the truck to 4,000rpm+, you will actually accelerate alot slower, then shifting lets say 500-800rpm eariler, due to trucks power and torque curve. all deseils though make peak power and torque generally at about 1000rpm or so before there trucks redline rpm.

understanding how the truck moves, and how/when the power and tq kicks in, helps you to always maintain strong acceleration and decent fuel economy.

so thus, my answer is shift into overdrive at about 3200rpm... -it will make sure that if you still need to punch it when in overdrive, atleast you will be between the maximum tq and hp figures, enabiling you to accelerate much quicker and use alot less deseil.

hope this helps.....though if your engine max rpm is at 6,000 then shifting at 4,000-5,000 would be ideal..... (to further check, get your truck/car dynoed and check the tq/hp curve)

[Plus]

In "overdrive" - RPM go down, in direct drive they will go up to normal. The engine is rotating more slowly at the same speed and in theory will use less fuel.

I think the confusion lies in the fact that by default "overdrive" is always on. When you click the button, it goes off and RPMs go up.

[wilko]

In "overdrive" - RPM go down, in direct drive they will go up to normal. The engine is rotating more slowly at the same speed and in theory will use less fuel.

I think the confusion lies in the fact that by default "overdrive" is always on. When you click the button, it goes off and RPMs go up.

Not confused... when you are in "Overdrive" the rpm go down....assuming you stay at the same speed.

It used to be a solenoid operated "extra" ratio operating after the gearbox so would give youa higher gear in any ratio it was set to work in.

It was particularly useful on long distnce cruising, or on the old 3 speed manual gear-boxes (and 2 speed automatics) in the 50s 60s and 70s as it if effect turned them into 5 speed boxes, giving 5 different ratios. However on a 4 speed box this really didn't work as the lower ratios ended up more or less the same...i.e. O/D 2nd = D/D 3rd, O/D 3rd = D/D 4th...the only "new" ratio being O/D 5th.

On an auto it really is only useful as an extra top gear as you will pass through the lower O/D ratios anyway.

[Plus]

I'll go and re-check again later, but in my Toyota Overdrive is always on. There's a button to turn it off. I guess Strada has the same setup and the OP was asking about when to push that button (and turn it off).

[wilko]

to avoid confusion..."My question is when should I put it in overdrive seems to be like a lower gear."

if it's a lower gear it's not O/D

Edited May 28, 2008 by wilko

[Plus]

I suppose if OD button is on, it doesn't mean the car is in overdrive mode, it's just that if it's needed, the car will change to OD automatically.

Originally OD was designed as an extra gear for high speed cruising but in modern cars it appears to work differently deploy under speed limit in lower gears as well, more like an extra gear between the engine and the transmission. At least in my experience turning it off makes a difference regardless of the current gear.

[Tywais]

My Nissan Bluebird has an OD button (Automatic transmission) and the only time I engage it (that is, the position it shifts down in) is in the mountains. It works very well in that situation, press it in when I'm going up a steep incline and also when going down (engine breaking). I have a light on the dash that tells me if it is off, which I believe is the normal mode. Will have to look at the light when I drive home.

[wilko]

O/D can be deployed at any time but manufacturers usually restrict it to higher gears, one problem used to be if you enged it in a low gear the torque involved could cause damage.

Edited May 29, 2008 by wilko

[Plus]

In Toyotas the OD is supposed to be "on" at all times.