I've left the car on an inclined driveway the other day, just couple inches from the garage door. Much to my surprise, as soon as I put the transmission into R gear and released the brakes, the car started moving forward, towards the incline. I had to push the gas pedal just to stop the movement while thinking something like there goes my front bumper. Gees, it was scary! So, I've mentioned this to a service representative during the A1 service and he promised to look into it. When I came to pick up the car, I was told that there's nothing wrong with the transmission, all Acuras '98 and later behave this way. After I pointed out that my previous car, 2001 CL-S auto, didn't roll at all, the guy gave me Acura Service News from September 2001 saying the following:

A/T-Equipped Vehicles Roll Backwards on a Hill
if customers tell you, “My new Acura rolls backwards on hills as soon as I release the brake pedal, and my previous Acura didn't do this,” here's what to tell them: On '98 and later models with A/Ts, rolling backwards on a hill is normal. Depending on the severity of the hill, older A/Ts may do the same.
Never models are more inclined to do this because of these changes implemented to improve fuel economy:
The torque converter slip characteristics at idle have changed.
The rolling resistance of the tires has been reduced.
Friction in the drivertrain has been reduced.
Brake drag has been reduced. (This not only improves fuel economy but also increases brake pad life.)

Does this sound right to anybody?? The hill I'm talking about is only 15-17 degrees and I was the only person in the car.

 

I'd buy that. Sounds like a reasonable excuse to me.

 

 

http://acura-tl.com/forums/images/smilies/smooch.gif

 

Some ppl ever discussed this issue before. Under inclined slopes, you car may move toward to the incline under the motion of you switch to the differnt gear. 04TL cannot pick up the new gear right away, for whatever reasons Acura says, and will have a short moment's lag.

 

Fifteen to seventeen degrees is a pretty steep incline.

I would expect most automatic transmission vehicles to roll down that incline, even when in reverse. The reasons you stated would just make it more likely to happen.

For safety's sake you should always keep one foot covering the brake and the other working the throttle when you're starting off on a steep incline, otherwise, the effect is much like starting off on an incline in a stick shift vehicle.

 

Thank you all for the info. I was hoping that I was unfortunate to get a problematic tranny, since this is the first car over $30K that rolls in my experience. It seems that the modern A/Ts is getting closer and closer to manual leaving no excuse to choose automatic for the next car. I'll be attending BMW driving event this weekend in Philadelphia, going to try that new 330ci with manual transmission and 325ci w/auto. Now I'm eager to see if I made the right choice

 

Autos have torque converters, which allow for "give". All that means is if you're on an incline, your gear does not lock your car in that direction, you can roll down an incline anyway, especially if it's steep.

 

15-17 degrees is mountain driving terrain .