Will shifting by hand damage an automatic?
 

I recently learned that engine breaking is an effective methods of slowing a vehicle. Will downshifting to slow my auto (engine break) at an approaching red lights damage it?

I use low gears on mountain descents, but that is not the same situation because the gear matches the mph and rev's.

What's cheaper: brake pads or a new tranny?

Automatic is slowing down your vehicle when you aren't pushing the gas pedal. It does it slower than traditional transmission but it still does.

well, i downshifted once at an approaching red light going around 45mph and my service engine light came on :/

Didnt mythbusters cover this one?

I sometimes throw it in a lower gear if I see a cop and don't want to flash brake lights, I dunno about every red light though.

I've done that for years with my ford. It doesn't give a shit. D has better takeoff, and OD doesn't keep me at 34,000 RPMs at 60.

Brake repairs are free on BMW's, and you don't have to deal with breaking in a new tranny. I'll go with brakes. :thumbsup

P.S. Breaking in a tranny, just doesn't sound right.

:1orglaugh:1orglaugh:1orglaugh

is it tiptronic or generic automatic?

the cop will also look for your car dipping in the front, you need a car with active suspension that stops body roll

I wouldnt' risk it

An Automatic transmission down shifts as you slow anyway .. changing gears/down shifting manually to slow your self will do the same damage in an auto as it will in a manual .. they both use a clutch system..if you slam a manual transmission into a lower gear to slow your self drastically you are really taxing the clutch/tranny and drive train the same will happen in an automatic .. braking stops/slows the vehicle at the source .. the spinning wheels .. abusing your drive train MUCH less ... Racing technique 101 ..." brake hard before the corner ... down shift and power through ." nothing is said about use your gears to slow your vehicle ...

Wow.. congrats!

I have known this since the first lesson at a driving school :1orglaugh

Even tho an automatic downshifts when you slow down... it does just that, downshifts WHEN you slow down, not downshifts TO slow down which is what hes asking.

I asked earlier what kind of transmission he has, a tiptronic or a traditional full automatic cus even tho most drivers think they are in full control of shifts with a tiptronic tranny, they are not. A tiptronic transmission will NOT let you downshift to a dangerous gear or even a potentially dangerous gear. So its not the same as a manual where you can slap it in any gear and fuck your shit up.

As far as the racing technique, you are 100% correct... if you're racing. But i dont think this guy is talking about performance driving so it dosnt necessarily apply, especially cus hes not talking about taking high speed corners but instead approaching a red light.


If you have a tiptronic tranny, i wouldnt worry about it, you can downshift all you want but use logic. And NEVER downshift into first when slowing down. 2nd is the lowest you should go.

MY tranny slows down by pedalling backwards.

http://www.fugly.com/media/IMAGES/Gr...per_Tranny.jpg