engine braking and brake life

My 2015 DCLB V6 AT is only the 2nd AT vehicle I have owned out of many, the first being a 2004 Sierra 4x4 ext. cab that I got rid of for the Tacoma. I notice that pretty much everybody on here reports that they get 50k+ miles out of stock front brake pads, some 100k or more, and even more for rear shoes, whereas my old truck needed pads every 30k on both axles. I don't ride the brake or drive aggressively, although about 1/3 of my driving is in town.

I do notice that the Tacoma seems to have a lot more engine braking than my old truck, however. With the GMC, I always felt I was fighting the drivetrain when I braked, whereas with the Tacoma that does not seem to be the case, and the Tacoma will also sense when I am braking at speed on a downgrade and downshift.

I am thinking that the Tacoma AT transmission design and controls are part of what leads to relatively long brake life with these trucks. Thoughts? Does anybody have any insight or similar past experience? Or, maybe the brakes in my GMC were simply undersized for the vehicle.

 

tacoma tranny ecu is intentionally designed to brake more than the usual auto tranny setup

it makes a ton of sense when you are hauling 500 or more pounds in the back, it doesn't
help so much if you are a hypermiler and want to coast more

you can shift it....bop 5-n-5 or 5-4-5 to engine brake less in certain conditions

 

I grew up using manual transmissions and absolutely love this braking feature; I try to anticipate road conditions and manually downshift from 5-4 and 4-3 on my normal drives. I try to remember to tap the brakes to let followers know i'm slowing down tho. It just makes sense to let the logic in the tranny and abs to provide more control than just braking. Some will argue you're hurting the tranny, but really all I'm doing is anticipating the downshift that the tranny will do anyway..

 

I'd like to see the documentation on this. None of my previous experience has shown any engine braking in the automatic unless shifted from "D" to a lower gear. Never even heard of this 5-n-5 to alter engine braking either, but would love to read more about it if it is true.

 

there is no documentation I can point to specifically

it is self-evident when coasting down a ramp compared to 'some other AT vehicle'
and then the tacoma. the tacoma definitely drops you out of 5 into 4 (or 4 to 3) and
you can't -hypermile- with it unless you go to N and back to 5, or down to 4
and back to 5...then it goes to 5 and stays there allowing you to coast better and longer

it is great with a load in the back, it blows when it's empty and you want to coast.

anywho there are other mentions of the tacoma being really greedy to use engine drag
and a lower AT gear to slow you down on offramps or down hills, where other cars
or trucks let you coast much easier and faster. tacoma puts you down a gear pronto

 

It may be part of the Factory Towing Package (full package which adds oil cooler, tranny cooler, 710 cca battery and 130 amp alternator).
Anyway, it happens every time i brake when going down a hill, 5-4 shift.

 

You must learn that AT.

First the "heavy engine braking" is BETTER for MPG's as the engine is going into full fuel cut, zero fuel gets fed to the motor during normal off gas "coasting". You can actually feel it start to give fuel to the truck around 20mph if you are not touching the brakes, once you hit that speed it will start to "idle" again and it almost feels like you got a lil bump from behind.

Second the auto downshifting on hills. You can control that very easily. Say you go down a hill and it drops all the way down to 3rd. If you want to go straight back up to 5th coasting (not in fuel cut) go from D to N back to D. If you want to go up one gear at a time go D to 4 back to D. Also at any point if you want to "coast" that is the engine not in fuel cut simply go D to N back to D and what will start to feed the motor the idle fueling.

 

It's called something like "Downhill-Descent" I have it too, the dealer told me what it was when I bought mine last year but I think it's part of the towing package... Let me surf my manual pages

 

here in Florida it kind of bothers me when the tranny downshifts on the off ramp of the super slab but when we took the taco to the mountains it was awesome incredible that when I was on infamous 129 in North Georgia/ North Carolina and the what? 12+% grades the truck almost "knew" what to do and I def saved my brakes. We have been up there 100 times with various vehicles. The truck was awesome and I never had to ride the brakes to slow for the switch backs. Back on flat land.. eh... still a little un-nerving.

 

I first noticed the automatic downshift when driving in the western mountains of ME (big hills to somebody in CO, MT, WA, etc). I understand why it does it, but I still find it disconcerting.

Thanks for the advice on how to defeat it.

 

I see what you are talking about, however that is not engine braking, in the traditional sense. If the selector is in 5th gear, then NONE of the overrun clutches are engaged, which would give you a true "engine braking" condition. What you are experiencing (Which I have driven a lot of the 2nd gen Tacoma trucks in my shop for diagnosis) is what is called DFCO, or Deceleration Fuel Cut-Off. This is where when you take your foot off the gas pedal, the ECU actually shuts off the injectors. This improves fuel economy. A interesting side effect of this is that with no engine output at all for that short time, the vehicle will slow down quicker because there is no input at all from the engine. On an engine that does NOT have DFCO in the programming, when you take your foot off the accelerator the engine is still generating power because it is still actually "running". When DFCO is active, the engine technically is not running. DFCO is disabled when the engine RPM drops to the minimum speed in the programming.

 

I was actually talking to my fiance about this very thing this morning. I've noticed over the past few days of driving my new truck that it downshifts upon deceleration as well. I do have the tow package, so maybe it is just a part of that. It definitely is downshifting though. I watched the tach, and I could see the RPMs go up then they'd drop as I slowed, and it would downshift and tach up again, then drop down as I continued to slow. This happens with or without brakes being applied. I am a huge fan of it.

 

My 2010, without the factory tow package, exhibits this behavior too. Definitely downshifting. It seems though that this only happens when the downhill is steep enough that the truck will gain speed while coasting, and I've applied the brakes.

 

I have a button to turn this on in my truck. I tried it today and the light flashed the whole time it was on, but I didn't notice any difference when going down some steep hills. I gained speed until I breaked. I was not needing the feature, just trying to learn what the truck does. Does the light flashing mean it isn't engaged?

 

What button are you talking about?

 

I have a hill descent button to the left of the steering wheel. I read in the manual that it was to help control down hill speeds.

 

Firstly, that isn't what this thread was about. Engine braking and DAC are completely different. DAC uses the ABS to keep you at a set speed going downhill, and only works in 4wd low range. Put the truck in 4 low, come to a stop, engage DAC, and it will light up solid. Then the truck won't exceed 5mph (I think that's the correct speed). That's why it was blinking for you, it wasn't engaged.

 

Thanks! I was searching for threads about this and this was the closest I found. I'll try that out.

 

correct

 

I absolutely love it. Nothing drives me crazier than having to ride my brakes down a hill. Tap the brake, and the truck will do all the work for me.