I drive an automatic shift car and like to save use on my brakes by downshifting from D to 3 to slow the car down (for instance, when preparing to exit the highway). Typically I’ll shift to 3 at around 60 mph, at which point the tachometer shoots up to around 3,000 RPM and I get a nice, gradual deceleration on the off-ramp. I use the brakes to complete my stop, and then move back into D before accelerating again. Here are my questions: Am I risking damage to my transmission? Is the wear I am saving on my brakes worth the cost of whatever repair my transmission might eventually require because of this?
No saved money here, brake pads are cheap. You are slightly increasing the wear on your tranny, trannys are $$$$. I wouldn’t do it.
Agree, downshifting is good when descending a long or very steep grade, in order to put less load on the brakes and keep the from FADING.
Excessive downshifting in daily driving will cause extra transmission wear and result in expensive problems layer.
I agree completly with Doc…but,many new cars down shift automatically when you let up on the throttle (2010 4Runner) and get better gas mileage. I’m sure that’s not the reason but it doesn’t hurt. I routinely take it out of overdrive when I anticipate staying under about 30 mph in traffic. I’m beginning to think it’s not as big a deal if done judiciously, and I like driving around in lower gear, like my standards, until freeway speeds. I think it’s safer overall but wouldn’t do it as a matter of course and definitely not til speeds were below 30 to 40 mph and stayed there.
Does anyone have a route commonly traveled in mind where if they don’t downshift their automatic transmission they experience brake fade? My recolection for the last time I experienced it was in the late 60’s comming out of the Sierra Nevada’s, not a route I commonly travel or a problem I commonly experience.
I agree that modern brakes are no where near as susceptible to fade and I can think of only one mountain trip where it became an issue;
I took a test drive in a 2011 Toyota Sienna. The transmission is a 6 speed automatic and there apparently is no way for the driver to downshift the automatic transmission. There is a drive range and then a sport drive range which changes the shift points. Before I purchase one, I am going to see if there is a hill descent feature. We have this feature on our 2003 Toyota 4Runner, but we can also select a lower gear ratio.
Does it (2011Sienna) do it (downshift) automatically like the newer 4 Runner ?
I don’t know how the newer 4Runner works. The 2011 Sienna has sequential shifting, so I think it does the automatic downshifting. I’ll find out more Monday when I go back with my questions and possible make a purchase. The 2011 has a great interior layout. I was looking for a 2008 Uplander to replace the 2006 Uplander that I am selling to my son, since he needs better vehicle. My wife has convinced me that maybe I should buy a brand new vehicle for a change. I do like the fact that the seats in the Sienna fold flat into the floor. At my age, I do huff and puff to remove the seats from the Uplander. Maybe in my old age I am finally getting over my Studebaker Scotsman tastes.
Downshifting for exit ramps is not recommended by me. The transmission is the second most expensive part of the car. Give the CV joints a break too. Do it for fun if you want to, but not to save the brakes.
Thanks to everyone for these helpful responses! Guess I’ll leave off the downshifting in the automatic and save it for when I drive my other car (which has a stick).
Let us know how you like it (Sienna) if it does…if cars start coming with auto downshift every time you lift the accelerator, it would be an interesting tidbit in discussions like this.
Same caution applies there too to manuals. 
See Docnick’s comment.