Team-BHP (https://www.team-bhp.com/forum/)

-   Technical Stuff (https://www.team-bhp.com/forum/technical-stuff/)

-   -   Tips on driving an Automatic (https://www.team-bhp.com/forum/technical-stuff/5883-tips-driving-automatic-23.html)

My excuses if the below question is off topic, but I would like to know the life of brake pads for the ANHC or any similar AT car in general.

My last brake pad replacement was at 44k and now the car is at 59k, but the brakes seem to have lost their bite off late. Contemplating a change in the 60k service.
Inputs anyone?

40K brake pad life for an Automatic is great. Mine lasts for 30K avg. We have linea owners who has to change pads even before that despite being a manual. So it all depends on vehicle weight, pad compound and driving style.

Why do you have to change brake pads just because it has lost its bite? Do check the pad wear and get it cleaned.

Usually while driving a manual car i disengage clutch while braking hard as it gives better control over deceleration. But in my VW Jetta 2.0tdi DSG the downshift takes place while the clutch engages and disengages for every cog down. This gives a feeling that while the brakes are trying hard to slow down the vehicle the clutch engagement at the same time opposes the deceleration. :banghead:
This one problem is a 1% dissatisfaction for me in the overall experience of using DSG'box. Should i get use to this ? Is this only for DSG or other normal auto boxes too ?:what:

No, the gearbox is not trying to oppose the braking, instead it's helping you with the engine braking! The practice which you have been following(engaging clutch while braking hard) is wrong at first place, you are not suppose to engage clutch till engine stalling point it reached(especially while braking from a higher speed). When you press clutch, you are robbing the whole braking of the car from the advantage of engine braking and putting the whole stress on the brakes when in turn increases the braking distance further! The DSG gearbox with downshifting while braking is contributing with th engine braking, this is what it is(and as a matter of fact any auto gearbox) supposed to do.

^^ True. The practice of disengaging the clutch before or in sync with braking is not the practice to be followed. Shift down to have effective engine braking. In fact depressing the clutch pedal will only result in the vehicle speed increasing as this nullifies the engine braking effect happening when you take your leg off the accelerator pedal.

No, the gearbox is not trying to oppose the braking, instead it's helping you with the engine braking! The practice which you have been following(engaging clutch while braking hard) is wrong at first place, you are not suppose to engage clutch till engine stalling point it reached(especially while braking from a higher speed). When you press clutch, you are robbing the whole braking of the car from the advantage of engine braking and putting the whole stress on the brakes when in turn increases the braking distance further! The DSG gearbox with downshifting while braking is contributing with th engine braking, this is what it is(and as a matter of fact any auto gearbox) supposed to do.

^^ True. The practice of disengaging the clutch before or in sync with braking is not the practice to be followed. Shift down to have effective engine braking. In fact depressing the clutch pedal will only result in the vehicle speed increasing as this nullifies the engine braking effect happening when you take your leg off the accelerator pedal.



Okk. Thank you for the safety tip.
Here is one scenario-
I am crusing at 100kph in 5th gear at 2000 rpm in a manual car. Suddenly spotting a speedbreaker, i press hard on brakes while leaving the clutch untouched. My speed drops to 40kph and engine at 1000rpm while still in 5th. Should i downshift or only utilise that much engine braking available for 5th gear (since engine speed will fall below 1000rpm and start lugging) and then rely solely on brakes for the last seconds of speed shedding ?

I read that line a few times to make sure I read it right. You downshift and use engine braking to have better control while braking, not the other way around by disengaging the clutch! Your control is compromised with the engine disconnected from the wheels. If you need better control, please use engine braking by downshifting. It takes a lot of load from the brakes and gives you better braking efficiency.

If you are at 100 in fifth, and down shift to 4th and then to 3rd, your engine itself gets you to about 40-50 without having to touch the brakes.
What I myself usually do is touch the brake lightly to let my intensions be known to driver of following car, and briskly down shift in a way that downshifting doesn't let RPM shoot beyond 3000-3300. If need be I may brake harder, but the downshifting remains constant, it is only when speed comes to idle RPM in second about 15 kph that I shift to Neutral. This prevents lugging, or anti stall trying to accelerate the car.



Rahul

Downshifting helps your braking so if you need to quickly depress the clutch in order to downshift, that's not a bad thing at all. The benefits besides better braking, are that your car will be more responsive to quick steering input leading to better ability for directional changes during emergency situations and also, you will be in the right gear to push off once you're done braking instead of later looking like a stupid cab driver fumbling with the gearbox before getting away ;)

Thank you guys. Will surely try to follow this standard braking practice from now onwards.

Hey guys, just reviving this thread for a bit. I found this interesting article about DSG transmissions.

http://forums.vwvortex.com/showthrea...ips-and-Tricks

With reference to this, a couple of points I wanted to question and see if they're still relevant to the modern day DSG in today's VW/Skoda cars.

Quoting the relevant bit from the article

Tip - Increase Throttle Position *Before* a Downshift, Not After.
Accelerator position is a major KEY in influencing the alternate gear selection. While there are many, many factors that go into telling the brains of the DSG what gear to switch the alternate gearbox into (And its impossible to get a handle on them all), "Intent" is a huge one. The DSG uses the throttle position to determine if you are thinking of accelerating (queues up a lower gear for performance) or not accelerating / decelerating (Queues up a higher gear for economy) -Seems pretty "Duh" right? If you are wanting to accelerate, you put the pedal down. If you don't want accelerate, you let off the throttle or hold it at minimal. Nobody would argue with that. But what you may not think about is that if you are used to driving a manual, and are now driving a DSG - your habits may *actually confuse* the DSG and make it think you want the opposite of what you are about to do. Here is what I mean. Lets look at a manual transmission driving scenario for downshifting from 3rd to 2nd to accelerate :

Let off Accelerator -> Clutch In -> Downshift -> Accelerate / Clutch Out

So now lets say you do the same thing in a DSG, so out of habit you do everything but the clutch :

Let off Accelerator -> Downshift -> Accelerate

If you do this (Which I found is exactly what I did) - This actually gives the DSG the wrong idea. If you are not on the accelerator, it assumes you don't want to accelerate. It assumes you want economy, not performance. So the alternate gearbox had a higher gear (4th) instead of a lower gear (2nd) chosen. Boom. You just caused an 800ms gear change instead of a 200ms one, and during that time you were off the accelerator during a time you could have been on it (You dont have a clutch now, you dont have to let off!) so you didnt even have propulsion the whole time you could have.

So what if you broke the habit to let off the accelerator before a shift, and instead pressed the accelerator down *then* changed gears? You're letting the DSG know you want to accelerate - It will have the lower gear ready for you because you are telling it from the pedal position you want performance - not economy. Breaking this single habit was personally a game changer for me

Is this true? If you want to guarantee a quick downshift, you punch down the accelerator in your current gear and THEN shift down? Wouldn't that make the car a bit unpredictable, especially if you're trying to make that quick overtake on a single-lane highway?

Also, how confused does the DSG get when you have to downshift two gears? Does it have a brainfreeze? Or can newer DSG units cope with it with minimal lag?

Note - I don't currently own a DSG automatic, but am planning to buy the GT TSI. Asking these questions so that I can hopefully make up my mind :)

Hey guys. Which is the most efficient way to idle at traffic signals?

1. Neutral + Parking Brake applied

OR

2. Drive + Foot Brake pressed

I've gone through various links and forums, and found that some strictly mention NOT to idle in Neutral, whereas, few others suggest otherwise. If someone here can list out the pros and cons of each of the ways, then it would be great.

Thanks!

At one time AT cars had both heavier brakes and they also lasted less. Today the use the same brakes but the AT brakes do last less. Why, no engine braking in ATs.

It depends upon what kind of an automatic you are speaking about. In a regular AT, leaving it in drive will keep the torque converter pumping fluid and trying to move the car like how you do in a manual transmission. However, due to the brakes, the car will stand still. Hence, when you let go of the brakes in drive, it moves instantaneously. Hence, for a torque converter AT, its best to keep the car in Neutral or Park. Note that the only difference between neutral and park is that in Park, there is a locking mechanism that prevents the wheels from rolling freely, more like leaving the vehicle in gear while engine is off. In both cases, the torque converter is disengaged, thus putting no load on any component.

In a signal, if you stop in Drive mode with foot brake, the torque converter may heat up during prolonged standing. Instead, its best to put to neutral and either use the main brake or the parking brake.

For an AMT, the clutch is disengaged as soon as brake is pressed or handbrake is applied. Hence, be it in drive or neutral, there is no wear and tear taking place, except that the clutch will be kept pressed in drive whereas in neutral it will be released.

If you drive a conventional AT, I would suggest option 1. , with either parking brake or main brake pressed depending upon the duration of the stop.

Thanks a lot! :)

Yes I'm talking about a regular AT, Ciaz, to be specific.

Another quick question - are there any special techniques, specific to AT cars, to get the maximum fuel efficiency? I have been getting 11-12 kmpl in city with all time AC ON. Tyre pressure 30psi in both front and rear, and I don't floor it as well while driving.