Auto - D v Manual mode on the freeway (5th gear)

[itr025]

I've had my Euro for under a month and had a question for fellow Auto owners.

Basically since I'm still running it in, I'm varying the revs and throttle when I drive in to work on the freeway. This is fairly easy given the traffic chaos in the mornings. Anyway, when I'm in 'D' doing 100ish (2200rpm?) and slow down to 70 (1800rpm), the gearbox doesn't down shift for me when I try to accelerate again and just labors the engine in 5th. Even if I release the throttle and press it halfway (I haven't tried much further because it's already laboring the engine).

However, if I move it to Manual Mode (Tiptronic?) the tranny stays in 5th, but the revs rise to about 2500 (torque converter is 'slipping'?) and lets me accelerate a lot easier. When I get back to 100 or so, it 'engages' back to 2200rpm. Is this normal behavior? I would've thought the behavior should be the other way round to make D easier??

Perhaps this is because the tranmission has learned my 'run in' throttle patterns and gone into super economy mode?

[aaronng]

To get it to downshift in D, give it more throttle. It should downshift to 4th and you won't lug the engine.

[clowdz]

I've had my Euro for under a month and had a question for fellow Auto owners.

Basically since I'm still running it in, I'm varying the revs and throttle when I drive in to work on the freeway. This is fairly easy given the traffic chaos in the mornings. Anyway, when I'm in 'D' doing 100ish (2200rpm?) and slow down to 70 (1800rpm), the gearbox doesn't down shift for me when I try to accelerate again and just labors the engine in 5th. Even if I release the throttle and press it halfway (I haven't tried much further because it's already laboring the engine).

However, if I move it to Manual Mode (Tiptronic?) the tranny stays in 5th, but the revs rise to about 2500 (torque converter is 'slipping'?) and lets me accelerate a lot easier. When I get back to 100 or so, it 'engages' back to 2200rpm. Is this normal behavior? I would've thought the behavior should be the other way round to make D easier??

Perhaps this is because the tranmission has learned my 'run in' throttle patterns and gone into super economy mode?

Given my very limited knowledge of Automatic Transmissions... It could be that when you're in 'D' the transmission has locked straight to the driveshaft and no longer using the torque converter. In some cars I believe it's called 'Over Drive', where the driveshaft engages directly to the engine on a 1:1 ratio at some given speed / rpm. This will give your car higher efficiency as it's no longer losing power through the torque converter when crusing at high speeds.

[adammet04]

Agreed with arronngg

and add my 2c's

in my opinion:
The auto trans in the car can (in my opinion) *learn* ( i use the term loosley) your driving habits, hence if you are accellerating slowly (which sounds like it because you got a new car and are in baby stage (no offence) ) the 5th can proably handle your acceleration, giving it a bit more will get the shift to 4th occurring ..

Eg: when i take the car on the GOR the car never finds 5th gear :) and barely finds 4th..because of how i drive the car through there that particular section..

I believe it has to do with the cars electronic system , if it senses x speed and for certain amount of time then it chooses best gear to run at to maintain speed and driving habit..


My car also changes rev's for tiptronic when in different gears compared to D mode..

[itr025]

Agreed with arronngg

and add my 2c's

in my opinion:
The auto trans in the car can (in my opinion) *learn* ( i use the term loosley) your driving habits, hence if you are accellerating slowly (which sounds like it because you got a new car and are in baby stage (no offence) ) the 5th can proably handle your acceleration, giving it a bit more will get the shift to 4th occurring ..

Eg: when i take the car on the GOR the car never finds 5th gear :) and barely finds 4th..because of how i drive the car through there that particular section..

I believe it has to do with the cars electronic system , if it senses x speed and for certain amount of time then it chooses best gear to run at to maintain speed and driving habit..


My car also changes rev's for tiptronic when in different gears compared to D mode..

Thanks people. I agree it's probably learnt my 'babying' driving style. Without having to search through the owners manual, how do you 'reset' its learning? Or do I just have to drive like a maniac and get it to learn that 'style'? lol.

[_CiVIC_]

i haven't had the problem... i usually step on it hard entering the freeway... so from 60-70 i nail it up to 110... i like the kick it gives...

but i have a weird problem on the car too... when i'm at a set of lights, then the light goes green, when i release the brake to start moving forward the car feels like its jerking.... don't know wtf it is...

[aaronng]

Thanks people. I agree it's probably learnt my 'babying' driving style. Without having to search through the owners manual, how do you 'reset' its learning? Or do I just have to drive like a maniac and get it to learn that 'style'? lol.

You don't need to reset anything. When you want it to downshift to 4th or 3rd at 70km/h, you give it more throttle than you usually do. It'll downshift and won't lug your engine. After a few times, the ECU will learn that you frequently downshift and will start to downshift with less throttle application.

[aaronng]

but i have a weird problem on the car too... when i'm at a set of lights, then the light goes green, when i release the brake to start moving forward the car feels like its jerking.... don't know wtf it is...

Same thing happens to our auto Astra. The torque convertor just disengages when stopped with the brakes applied. When you let go the brakes it re-engages and you get a little bump forward.

[_CiVIC_]

Same thing happens to our auto Astra. The torque convertor just disengages when stopped with the brakes applied. When you let go the brakes it re-engages and you get a little bump forward.

i'm not talking about the nudge forward... thats normal... i'm talking about the shaking feeling of the car... like its shivering or something :confused:

[aaronng]

i'm not talking about the nudge forward... thats normal... i'm talking about the shaking feeling of the car... like its shivering or something :confused:

If I let off the brake and press the accelerator before the torque convertor engages, then the car shudders like it was dying.

[_CiVIC_]

If I let off the brake and press the accelerator before the torque convertor engages, then the car shudders like it was dying.

nah thats not it...

when i gradually let go of the brake and then go to apply the accelerator it shudders......... its due for service on the 16th of december... lets see what honda says..

[aaronng]

nah thats not it...

when i gradually let go of the brake and then go to apply the accelerator it shudders......... its due for service on the 16th of december... lets see what honda says..

Hope it goes well and they manage to fix it quick and easy.

[BiLL|z0r]

To help with both questions:
1) My auto doesn't shudder that I've ever noticed.

2) It doesn't take long for the car to relearn your driving technique. Some days I have a "boy racer" day and the car quickly thinks it's always in a race, other days I have a "use as little fuel as humanly possible" day and it changes within an hour or so of constant driving. My auto downshifts ok on the highways but sometimes a little too late. If I know I'm going to overtake someone I'll whack it into Manual mode and shift into 3rd about 1/2 a second after stumping on the accelerator, then woosh away I go. I'f I'd like to accelerate a little quicker from say 70 to 100 then I'd use 4th in manual but D works well 95% of the time.

[kleung]

Aaronng - The Astras have that 'true neutral' thing don't they, where they automatically completely disengage the transmission when stationary? It's supposed to save fuel or something.

itr025- When you see the revs rise slightly when knocking the shifter over to 'manual', that is the torque converter 'unlocking'. Clowdz pretty much nailed the explanation of how the lockup torque converter works, except that 'Overdrive' is not the 'locked' torque converter.

I've also found that the speed at which you increase throttle also influences kickdown. If you gradually roll on throttle, the transmission is less likely to kickdown than if you just stand on the throttle. Once you get to know the car better, you'll know exactly how you have to use the throttle to get kickdown.

All that said, I've got to say that the Euro has one of the smartest auto boxes I've experienced. It was a complete revelation coming from the awful 4AT on my old Berlina. I'd even go as far as to say that it's right up there, if not better than the BMW autos.