Question re Automatic Transmission Driving Technique

**matty** · March 22nd, 2006 02:16 PM

Guys! I have a question re A/T. I have a new car with A/T and i'm having a hard time adjusting to it since all my life i have been driving a manual. There are a lot of things that confuses me. Maybe some of you can help and clarify it once and for all. When in stop and go, should I still shift to N or just remain in D with the brakes pressed or hand brake? How about in stop lights, is it better for my transmission to just stay in D with the hand brake or should I move it to N? I am confused since some people say its ok to shift from D to N when the car is not in motion but some say it is bad for the transmission. Medyo magulo na talaga. Please help. I want my new car to last and be able to drive it correctly para tumagal yung transmission without defects. Thanks a lot!

**falken** · March 22nd, 2006 02:18 PM

Put it in neutral whenever you stop.

**theveed** · March 22nd, 2006 02:23 PM

You don't need to shift to N, when you press the brakes fully and the car isn't moving, there's no need to shift to N, makes little to no difference. Same token, won't hurt if you do shift to N.

But based on logic, the less you move the shifter, the less wear on your control cable and torque converter (since it has to re-engage when you shift to D again).

Personally, unless it's a long stop, I let it stay in D. If it's a really long stoplight stop or I have to park, then it goes to P + handbrake.

**av8or5** · March 22nd, 2006 02:33 PM

since the beginning of my driving experience and from reading car manuals, it is mentioned not to move the shift level from "D" to "N" when in stop and go traffic.i know that it is more smooth if its in N while waiting for the light to turn green, but the movement from N to D to N and vice versa has more wear and tear as "Theveed" mentioned previously. if you notice, there is a slight jump from N to D. so best practice is to remain in "D" and only shift to N if its more than 1 minute waiting period for the light to turn green.
I was taught that in drivers education back in high school, although they taught and gave more reasons why it should be left in "D" while at a stop light.

**jaeger** · March 22nd, 2006 02:40 PM

on your concern to be able to drive it correctly . . . .

most auto-trannys have pre-set shift points. Some have economy and power buttons (like mitsu's). Know your cars AT shifting points so you don't unneccessarily over-rev your engine. Also check the rpm when your torque converter locks up - this is when you have a speed gain of say from 60 kph to 80 kph but your rpm remains pegged at 2,000rpm - that's your torque converter locking up (wala nang slippage) delivering additional speed without engine having to rev up higher (this was on my old D16Y8 AT).

Drive it right, an AT doesn't necessarily mean higher fuel consumption.

**wulf** · March 22nd, 2006 02:41 PM

how bout downhill,guys?leave it in D or freewheel on N like on a manual tranny?i always do D but i'm just thinking maybe i'll save on gas if its not on drive

**66bunny** · March 22nd, 2006 02:45 PM

Just don't make it a habit to stay in "D" for too long. My friend fell asleep one time and he woke up with a thud.

Nakatulog, umangat ang paa sa brake. Bangga sa bumper ng auto sa harap niya. If it will take more than a minute, put it in N then handbrake.

Play heavy metal music para di antukin. Optional.

**niky** · March 22nd, 2006 02:50 PM

I have one very good reason for you to shift into N at the stoplight. ATF temperature.

Whether or not you shift into Neutral, your torque converter will have to re-engage anyway when you pull out from the stoplight, as it's disengaged completely at idle. I usually just shift back into D before releasing the brakes.

While the torque converter is disengaged at idle, it's still connected as long as you're in D. While you're in D at a stop, there's more friction, as the torque converter is torn between the transmission wanting to push the car forward and the brakes holding it back. This causes more heat in the Automatic Transmission Fluid as it is pushed through the torque converter, and more pressure on the brakes.

Hot ATF in traffic can cause premature wear of the transmission. Hot brakes also wear down more quickly. There's a reason AT cars eat up brake pads like rice cakes and require new brake discs more often than manuals.

Most driving instructors don't want you to shift into neutral while the car is moving, as you can't react to road emergencies right away, but at the stoplight, you're not going anywhere anyway.

So... if the light has just turned red... shift it into N. Save yourself some brake pad, and keep your ATF cool.

**niky** · March 22nd, 2006 02:54 PM

Oh, downhill? Leave it in "D". Or "2" if it's a steep descent. More controlled. Not good for your ATF if you're freewheeling the whole time, but safety first.

**yebo** · March 22nd, 2006 02:55 PM

Originally Posted by wulf

how bout downhill,....freewheel on N ...save on gas if its not on drive

that is the best way to damage an auto tranny, moving while on N.

that is why the manufacturers recommend that if a car with auto tranny will be towed that the drive wheels be lifted, because the tranny must never be shifted to N (or P!) if the car is moving.