Question On Auto Gear Selection

[lolmd]

Hey guys, I am a bit confused with the auto gear set up on my Mazda familia. They are set up like this:

P

R

N

D3

S2

L1

I know what the P,R,N are for and I use the D3 to drive, but what confuses me is why do they have D3 instead of just D? and what are the S2 and L1 for? I do not have the exact owner's manual for this model, so please excuse the stupid question. Thanks!!

O.K I figured out what the S2 and L1 are for. But having only a D3 instead of a plain D confuses me. I know that D3 is supposed to be for stop and go traffic, but what if I wanted to engage the fourth gear on a clear stretch of road, how to do that?

Edited August 30, 2011 by lolmd

[The Stig]

Hey guys, I am a bit confused with the auto gear set up on my Mazda familia. They are set up like this:

P

R

N

D3

S2

L1

I know what the P,R,N are for and I use the D3 to drive, but what confuses me is why do they have D3 instead of just D? and what are the S2 and L1 for? I do not have the exact owner's manual for this model, so please excuse the stupid question. Thanks!!

O.K I figured out what the S2 and L1 are for. But having only a D3 instead of a plain D confuses me. I know that D3 is supposed to be for stop and go traffic, but what if I wanted to engage the fourth gear on a clear stretch of road, how to do that?

okay lets start from scratch

L1 = this only engages the 1st gear and is mainly used for when you are towing some sort of weight

S2 = not very important in countries like SL but is mainly used for driving downhill and for driving on snow and only uses 1st and 2nd gear.

D3 = its mainly for city driving and only uses 1st,2nd and 3rd gears

As for your other question your car should have an overdrive mode on the gear lever or some button nearby. use that when you are cruising outstation. (usually marked as OD)

Edited August 31, 2011 by The Stig

[evergreen]

okay lets start from scratch

L1 = this only engages the 1st gear and is mainly used for when you are towing some sort of weight

S2 = not very important in countries like SL but is mainly used for driving downhill and for driving on snow and only uses 1st and 2nd gear.

D3 = its mainly for city driving and only uses 1st,2nd and 3rd gears

As for your other question your car should have an overdrive mode on the gear lever or some button nearby. use that when you are cruising outstation. (usually marked as OD)

u mean to keep the OD on?

[lolmd]

okay lets start from scratch

L1 = this only engages the 1st gear and is mainly used for when you are towing some sort of weight

S2 = not very important in countries like SL but is mainly used for driving downhill and for driving on snow and only uses 1st and 2nd gear.

D3 = its mainly for city driving and only uses 1st,2nd and 3rd gears

As for your other question your car should have an overdrive mode on the gear lever or some button nearby. use that when you are cruising outstation. (usually marked as OD)

Thanks for clarifying Stig. I managed to find a manual for the 2001 protege. And according to this manual there is an overdrive mode button on the gear lever. However it works in a funny way, overdrive is on by default. Pressing the button cancels overdrive. The manual suggests canceling overdrive in stop and go traffic. When you press the button on the gear lever and cancel overdrive an indicator lights up on the dashboard. Confusing isn't it?This is what the manual for the 2001 protege says:

[b]Overdrive operation

In D, the transaxle automatically shifts to

overdrive, which improves fuel economy

and reduces noise.

To allow engine braking when going

down a steep grade, make sure the

overdrive button is in the off position

And for a smoother ride with less shifting,

don’t use it when:

• Going up a steep grade.

• Driving in stop-and-go traffic.

• Pulling heavy loads.

To turn off the overdrive, push the

button.

The transaxle will then shift through a

three-gear sequence in D.

Shift patterns without overdrive:

D = 1st, 2nd, 3rd

2 = 2nd

1 = 1st

To turn it on, push the button again.

Shift patterns with overdrive:

D = 1st, 2nd, 3rd, 4th

2 = 2nd

1 = 1st

[/b]

In my 1999 BJ model, D is marked as D3 which added to the confusion.

Anyway I have it sorted out now, Thanks!

[The Stig]

u mean to keep the OD on?

Yes keep it on always unless you dont want your car to shift to 4th like in a situations where engine braking is required while going downhill.

Thanks for clarifying Stig. I managed to find a manual for the 2001 protege. And according to this manual there is an overdrive mode button on the gear lever. However it works in a funny way, overdrive is on by default. Pressing the button cancels overdrive. The manual suggests canceling overdrive in stop and go traffic. When you press the button on the gear lever and cancel overdrive an indicator lights up on the dashboard. Confusing isn't it?This is what the manual for the 2001 protege says:

[b]Overdrive operation

In D, the transaxle automatically shifts to

overdrive, which improves fuel economy

and reduces noise.

To allow engine braking when going

down a steep grade, make sure the

overdrive button is in the off position

And for a smoother ride with less shifting,

don’t use it when:

• Going up a steep grade.

• Driving in stop-and-go traffic.

• Pulling heavy loads.

To turn off the overdrive, push the

button.

The transaxle will then shift through a

three-gear sequence in D.

Shift patterns without overdrive:

D = 1st, 2nd, 3rd

2 = 2nd

1 = 1st

To turn it on, push the button again.

Shift patterns with overdrive:

D = 1st, 2nd, 3rd, 4th

2 = 2nd

1 = 1st

[/b]

In my 1999 BJ model, D is marked as D3 which added to the confusion.

Anyway I have it sorted out now, Thanks!

Yes OD in this context actually works as the 4th gear itself

http://auto.howstuffworks.com/automatic-transmission9.htm

So in short keep the OD on even in traffic cause it will give you better mileage where as turning it off will give you better torque which would not be of much use if you arnt carrying a huge load.

Also note that turning the OD off when you are going downhill will actually help your car brake better (engine brake) which would be the only practical situation where you would want to turn it off

[lolmd]

Yes keep it on always unless you dont want your car to shift to 4th like in a situations where engine braking is required while going downhill.

Yes OD in this context actually works as the 4th gear itself

http://auto.howstuffworks.com/automatic-transmission9.htm

So in short keep the OD on even in traffic cause it will give you better mileage where as turning it off will give you better torque which would not be of much use if you arnt carrying a huge load.

Also note that turning the OD off when you are going downhill will actually help your car brake better (engine brake) which would be the only practical situation where you would want to turn it off

Yep, Thanks for the link. That makes sense.., now if I would only remember to turn it off when going down hill luckily there aren't too many hills on my usual commute

[Sifaan]

Yes OD in this context actually works as the 4th gear itself

http://auto.howstuffworks.com/automatic-transmission9.htm

So in short keep the OD on even in traffic cause it will give you better mileage where as turning it off will give you better torque which would not be of much use if you arnt carrying a huge load.

Also note that turning the OD off when you are going downhill will actually help your car brake better (engine brake) which would be the only practical situation where you would want to turn it off

this description used to confuse me when we had the march (well, it still confuses me, but now it's only academic as we sold the car!)

if OD "acts like a 4th gear" then it should not have an impact on other gears?

So it wouldn't make a difference to have it on or off in traffic?

I think (but not sure) that a better description is that it modifies gear ratios to give more speed/less torque - great for easy driving but not so great if you want more "pickup"?

as for when to use it, in the march it helped to have it off when going uphill and overtaking (even in city speeds) rather than "standing" on the accelerator; but that car had a bad power-weight ratio so that maybe does not apply to the familia.

btw the convention on the indicator - the manufacturer generally expects it to be kept ON except when you turn it off for a specific reason, and the indicator comes on to remind you that you have it ON.

[lolmd]

this description used to confuse me when we had the march (well, it still confuses me, but now it's only academic as we sold the car!)

if OD "acts like a 4th gear" then it should not have an impact on other gears?

So it wouldn't make a difference to have it on or off in traffic?

I think (but not sure) that a better description is that it modifies gear ratios to give more speed/less torque - great for easy driving but not so great if you want more "pickup"?

as for when to use it, in the march it helped to have it off when going uphill and overtaking (even in city speeds) rather than "standing" on the accelerator; but that car had a bad power-weight ratio so that maybe does not apply to the familia.

btw the convention on the indicator - the manufacturer generally expects it to be kept ON except when you turn it off for a specific reason, and the indicator comes on to remind you that you have it ON.

For Overdrive, the indicator comes on to remind you that it is OFF. As being ON is the default position. This is what it says in the manual:

O/D OFF indicator light

This light comes on when the overdrive

has been turned off.

[The Stig]

this description used to confuse me when we had the march (well, it still confuses me, but now it's only academic as we sold the car!)

if OD "acts like a 4th gear" then it should not have an impact on other gears?

So it wouldn't make a difference to have it on or off in traffic?

I think (but not sure) that a better description is that it modifies gear ratios to give more speed/less torque - great for easy driving but not so great if you want more "pickup"?

as for when to use it, in the march it helped to have it off when going uphill and overtaking (even in city speeds) rather than "standing" on the accelerator; but that car had a bad power-weight ratio so that maybe does not apply to the familia.

btw the convention on the indicator - the manufacturer generally expects it to be kept ON except when you turn it off for a specific reason, and the indicator comes on to remind you that you have it ON.

When i said "acts like a 4th gear" it actually is the 4th gear, see the in the olden days the maximum input:output gear ratio cars had was 1:1 the equivalent of 3rd gear in modern cars. But they installed a separate unit to bring down the ratio in order to achieve better cruising speeds and efficiency.Today there is no separate overdrive unit, the overdrive itself is embedded as a 4th gear, but the term is still in use thus creating loads of confusion

"I think (but not sure) that a better description is that it modifies gear ratios to give more speed/less torque - great for easy driving but not so great if you want more "pickup"?"

Not exactly machan, turning it off doesn't modify gear ratios but it simply removes the 4th gear.

AFAIK the OD wont change the timing of the gear changes as opposed to something like sports mode which would increase the gear shifting rpm range.

See when you drive at the optimum shifting rpm range (usually biased towards economy) the gears up shift e.g from 3rd to 4th at around 3500rpm (just a wild guess on the rpm range)

but if you dont have a 4th gear (turning off OD) the gearbox cant up shift meaning it will let the engine rev until it hits the rev limiter giving you more top end torque (this explains your theory on turning off OD when overtaking)

As for the usage i'd say keep it on always except for the times you need engine braking and when you need that extra bit of torque while overtaking .