3 Questions About The Automatic Transmission

[japthree]

3 questions about the automatic:

1.When the headlights are on and dashboard is lit up why is the indicator light for 'D' (drive) a very pale green but the other gears except 'R' a brighter green?

2.When you stop at the lights and 'a pause becomes a wait' I put the handbrake on. Are you supposed to shift to 'N' or can you keep it in 'D'?

3.The Owner's manual talks about using gears 'L' '2' and '3' for more engine braking (which autos lack when compared to manuals?) and when going up/down hill.

I find the car more in control if I'm in '3' going round a tight bend or windy road. Is this correct - what other times would you use these please?

Sometimes I get bored that my left hand is not doing anything -- I just shift to '2' and '3' for the fun of it -- I miss 'changing gears' now. Maybe I should get a manual!

Thanks!

[Parthiban]

1. I've always figured that D was slightly dimmer because it's on all the time, the others are brighter to make you aware you're not in the right gear (if you were in N at a set of lights for example)

2. I don't tend to put the handbrake on in D as I don't like the way the car tries to pull through it and the back of the car sits down...........up to you, but it doesn't feel comfortable at all

3. You can drop down gears whenever you feel comfortable to do so, if in a manual you would downshift at a particular point, no reason why you shouldn't do it in an auto. I often use the manual selector when I'm overtaking to engage the lower gear before I start rather than waiting for the kickdown after I've already started to overtake.......

[SHAHZ]

3 questions about the automatic:

1.When the headlights are on and dashboard is lit up why is the indicator light for 'D' (drive) a very pale green but the other gears except 'R' a brighter green?

Same as what Parthiban said

2.When you stop at the lights and 'a pause becomes a wait' I put the handbrake on. Are you supposed to shift to 'N' or can you keep it in 'D'?

If you put the handbrake on then id shift into N......i just sit there with my foot on brake

3.The Owner's manual talks about using gears 'L' '2' and '3' for more engine braking (which autos lack when compared to manuals?) and when going up/down hill.

I find the car more in control if I'm in '3' going round a tight bend or windy road. Is this correct - what other times would you use these please?

Sometimes I get bored that my left hand is not doing anything -- I just shift to '2' and '3' for the fun of it -- I miss 'changing gears' now. Maybe I should get a manual!

I hardly ever use this to drop a gear i just put my foot down and let it kick down

Thanks!

[84Stoney]

SHOULD'A GOT A MANUAL!

[durg]

If you are in traffic and keep your foot on the brake or but the handbrake on, then you use a lot more fuel than you do putting it into neutral.

Using L, 2 and 3 is recommended when you are towing stuff - it give you more control over what's happening

[Parthiban]

If you are in traffic and keep your foot on the brake or but the handbrake on, then you use a lot more fuel than you do putting it into neutral.

Not actually true mate. Can't remember who pointed this out but modern cars have quite efficient fuel cut off systems.......

Easy way to illustrate it, next time you're in a traffic jam, shift the car from D to N, and you'll actually see the engine revs rise.....

[WylieCoyote]

If you are in traffic and keep your foot on the brake or but the handbrake on, then you use a lot more fuel than you do putting it into neutral.

Not actually true mate. Can't remember who pointed this out but modern cars have quite efficient fuel cut off systems.......

Easy way to illustrate it, next time you're in a traffic jam, shift the car from D to N, and you'll actually see the engine revs rise.....

Was't it Richard Hammond of Clarkson on Top Gear that said it? I know they were on about when you're slowing down for a roundabout you get a few yards for free!

Don't use the parking brake when it's in D. Yes it's good practice to put it into N when sitting in traffic.

Advanced driving teaches you that when driving to a speed limit, knock the zero off the speed and that's what gear you should be in (up to the limit of how many gears you have!). Therefore if you're driving at 30mph you should be in third as it gives the best balance of performance, engine braking and fuel economy. With that in mind, 20mph be in 2, 30mph (or even 40mph in a 4-speed auto) be in 3, anything more be in D. Use L, 2 and 3 for engine braking when on hills and so on. You're quite right - for anything remotely twisty, 3 is a good choice for the reasons above.

[durg]

If you are in traffic and keep your foot on the brake or but the handbrake on, then you use a lot more fuel than you do putting it into neutral.

Not actually true mate. Can't remember who pointed this out but modern cars have quite efficient fuel cut off systems.......

Easy way to illustrate it, next time you're in a traffic jam, shift the car from D to N, and you'll actually see the engine revs rise.....

If you look at the full output from the ECU when an auto car is running, then you see that as you shift from neutral to drive the load value on the engine increases (when you have the brake on and the car is stationary). This is because the engine now has resistance supplied by the torque converter and to overcome this it has to put more fuel in to maintain the required idle speed (and hence use more fuel). The reason the engine speed rises when you move from drive to neutral is because that resistance is then removed and the engine is allowed to run more freely (higher revs) until the ECU regulates it back to the standard idle speed. If you look at the CO2 output from and engine on a dyno it confirms this.

[DJ Wozza]

Advanced driving teaches you that when driving to a speed limit, knock the zero off the speed and that's what gear you should be in

I needed to be in gear 14.2 when I was in Germany then

This is my first Auto, love it to bits as I have to drive though cental London traffic very often.

It is just less stressful than all the up down on the clutch pedal.

[WylieCoyote]

LOL @ Wozza. Damn the 70mph UK speed limit. Let's all move to Germany!

[Hostile Smoker]

Another thing to bear in mind (that I found out from previous cars), if you are driving quite hard and your brakes have heated up, then you come to a halt at the lights and sit there with your foot on the brake, there is more chance of the brake pad material bonding to the discs and leaving residue behind - people often mistake this for warped discs but in fact it's just uneven disc surface due to the build up of melted on pads.

No idea if the Lexus suffers with this as I've not had mine long, but it's certainly a problem for other cars...

If I come to a complete halt I usually try to knock it into neutral and stick the handbrake on.

[WylieCoyote]

Another thing to bear in mind (that I found out from previous cars), if you are driving quite hard and your brakes have heated up, then you come to a halt at the lights and sit there with your foot on the brake, there is more chance of the brake pad material bonding to the discs and leaving residue behind - people often mistake this for warped discs but in fact it's just uneven disc surface due to the build up of melted on pads.

No idea if the Lexus suffers with this as I've not had mine long, but it's certainly a problem for other cars...

If I come to a complete halt I usually try to knock it into neutral and stick the handbrake on.

Good point actually. I'd never have thought of that reason in a million years!

[japthree]

1. I've always figured that D was slightly dimmer because it's on all the time, the others are brighter to make you aware you're not in the right gear (if you were in N at a set of lights for example)

could it be instead that if you drive in dull (no sunlight) daytime weather (especially when it is raining and/or motorways) and have a dark coloured car (according to the AA) it is good practice to drive in dipped headlights. But you can't always tell the lights are on as the dashboard lighting is hard to see -- but the green "D "would be dimmer with lights on than with lights off -- so you'd know you've got your lights on!

The other thing I like about the Auto is that you have to brake sooner/more (because of lack of engine braking compared to Manual transmission) so you give an earlier 'advance warning' to the driver behind you.