What's up everyone? I have been getting conflicting information about whether it is bad to use your engine for breaking, ie: Downshifting while coming to a stop. So, if anyone would like to comment, or give some more conflicting info, :lol: j/k

In my opinion it isn't bad for the engine........ I mean, they do it in the mountains all the time, right?

Thanks for your time,
Hans

dont down shift to brake. i assure you that brake pads are cheaper than transmissions. only reason people down shift in the mountains would be to not use yoiur brakes as much going down a mountain. ddecreases the chances of the brakes failing and i seriously doubt this would be a problem with the technology of todays brakes. so use your brakes, it what the were designed for.

yeah, when I come to a stop, I just put it into neutral. Thats how my dad taught me and when my friends blew their transmission, I found out how much cheaper brakes were.:)

I always downshift to slow down. Using the engine along with the brakes cuts down on the braking distance. It also will prolong the life of your brake pads. If you are smooth when you downshift and don't drop the clutch there should be no harm done to the transmission. The only vehicals that you really don't want to downshift to slow down is an automatic. The automatic does not handle the downshifts as well.

I think the Impreza manual that comes with the car says to downshift to increase brake pad life. That being said I don't do it. I'll downshift when I'm slowing down to a sustained slower speed, but not when stopping at a stop sign or light.

Using your engine to slow down is fine if you like maximizing the amount of money you spend. :p

Is it "bad" - not necessarily. Does it help you slow down - sure.

But it comes down to what TRP said - you're gunna want to replace brake pads more often than your clutch - or god forbid your tranny.

The time when you should use engine braking is in bad weather conditions - where you can achieve a similar effect as braking, but without the chance to "slide" and "slip" around.

So, is it the consensus, then, that while descending Pike's Peak, I should keep it in 5th and use only the brakes for deceleration?

Hahahaha::):):)

Originally posted by Jon [in CT]
So, is it the consensus, then, that while descending Pike's Peak, I should keep it in 5th and use only the brakes for deceleration?

Hahahaha::):):)
Actually.. I think that is still bad .. it might be better to put the car in neutral and just use the brakes all the way down. I think some people like the look of glowing brakes. :D :D :D

Is it still bad to downshift to slowdown if you rev match as you're shifting down? Why would this still be bad on the tranny if you're being smooth?

In my opinion, if you're driving the car aggresively, it will not handle idealy if you are turning in while in neutral. The balance of the WRX is completely a function of your pedal. If you don't down shift into a turn, you're not gonna be able to swing around the caboose (I'm talking track time here). If you practice rev matching, your tranny will be none the wiser. I personaly only downshift if I'm gonna be getting back on the gas (like into a turn), if I'm approaching a stop, I'll just put it in neutral and coast (unless I'm stopping from highway speeds). The brakes wear much faster at higher speeds, so for that reason I'll usually engine brake till 3rd gear, then toss it into neutral and coast to a stop for the light.

If you're going into turns in neutral (or below 3500RPM) you're missing out on a beautifully handing car.

-Pete

Clutch=$300
Brake Pads=$40

Here's what click and clack say:

when coming to a stop, just let the car deaccellerate while leaving it in gear. Use the brakes to slow down. Just at the point where the engine starts to bog (i.e. goes below 600RPM, put in the clutch and stop the car. then put it in neutral, first, whatever. That is teh easiest on the car.

HOWEVER, this is a performance car, and as such, you have the right, or obligation to replace parts with higher performance parts, i.e. race clutch, lightened flywheel etc. when they wear out.

:)

The clutch has nothing to do with compression braking if you rev match which I hope you guys are doing. It will not slip with that light of a load nomatter what you do. If you don't rev it up before you downshift it puts a shock load on the powertrain. It would be about the stress of a hard launch. All you are doing when you downshift to slow down is using the rotating mass of the engine/ transmission to create friction to slow down. It is creating no more friction than when you are driving normally. There is no fuel being burned off throttle. I see no harm in using this method to slow gradually.

using the engine to brake you (i.e. downshifting to slow/stop the vehicle) made sense back in the bad old days pre modern braking systems - and behaviors seem to take time to change. with modern brakes (and assuming we're talking cars here and not 18 wheel trucks or something) it makes more sense to just use the brakes.

Well I guess that not many people use their engine to slow down. It seems that most people use there brakes more often. I haven't had any problems from downshifting using rev matching then letting the car coastwhile applying the brakes. Seems to make more sense but then again I am not one of those people that start slowing down for a stop sign 2 miles early. Maybe I will try that to see how many more rotors I can warp from over heating.

Engine brake, rev-match, heel-toe, whatever on the track during competetive driving. ( If you drive "competitively" off the track, shame on you! ;) ) "Click & Clack" it while daily driving. Your Suby will last longer...IMHO. :D

Hehe, funny story about downshifting. I was riding in the back of a car with a afriend,while my other friend was testing out a Civic SiR with one of the dealers sitting in the front passanger seat. Well we were driving, then the light turns red. My friend downshifts to slow down(he doesnt even really use the brake) then the dealer is like" What the hell are you doing!" He was like"downshifting" Then the dealer said "Dont downshift. The cost of a brake pad is way less than the transmision!" My friend looked like he was scared bigtime. Me and my other friend silently laughed at him from the back:lol: :lol:. It was pretty funny.

Ummm folks???
How did this become a discussion?

A)If you know how to double clutch (or heel/toe if you're a rockstar)....

then do that to downshift. If done properly there is no wear to any drivetrain components. This will get you in a lower gear which will slow the car down more. Continue downshifting this way as needed to slow the car as quickly as you want. Then put the clutch in before you come to a stop.

B)If you do NOT know how to double clutch...

Learn...
OR
Leave the car in gear as one member suggested until you are about to stop, then put the clutch in before you stall your scooby.

----------------------------------------------------------
I'm no car genius, but it seems like simple questions such as this one get blown up into massive discussions when a simple response is all that is needed, and would be much more usefull to the person asking for help.

I hope I don't sound like a jack@$$...but this has happened to me when I'm looking for help and it can be overwhelming and frustrating.

just my 2 cents,
-Mike {flame suit on} :p

Mike, You are right on with that post.

I downshift from 5th to 4th to slowdown for off-ramps, or from 4th to 3rd for stoplights, then go into nuetral...

The funny thing is that my cars second gear is grinding bad now... (Got this car 2 months ago w/ 98k miles on it, and ive been using it to learn to drive stick)

Originally posted by Silver_Bell_WRX
Mike, You are right on with that post.

Woohoo...thanks for the backup Silver_Bell :)

I did a search and found that this thread has a long discussion of double clutching and heel/toe which was apparently ripped from a BMW site. It seems rather long and in depth...
http://www.i-club.com/forums/showthread.php?s=&threadid=87247

Here's another site w/info on Heel/Toe:
http://www.turnfast.com/tech_driving/driving_heeltoe.lasso


As an aside...since modern cars have syncros you don't have to get double clutching just right. It's the job of the syncros to match rpms. So don't get all worried about damaging your clutch by downshifting.

As far as heel/toe goes I'm gonna start practicing today...seems like that would help dramatically in an AutoX or any road/rally race.

-Mike

I've never had anything other than manual transmissions in my cars and I've always used engine braking without it ever causing any mechanical problems. Most of the time, I use a combination of engine and brakes. There are also times when using engine braking is more sensible than using the brakes (driving on slippery roads, for example).

One person mentioned putting the car into neutral while stopped at a light or intersection. I think this is a terrible idea. I have the car in first gear, foot on the clutch, one eye in the rear view mirror, and the other eye scanning right, left and ahead of me. I want to be ready to move out of the way when that preoccupied, cell-phone gabbing, SUV driving soccer Mom or sales guy comes barrelling my way. With the car in neutral, you're a sitting duck.

As far as sitting in 1st gear this is what I think.

When you try downshifting into 1st (while moving) with the clutch fully depressed you will find that you can't move the shifter from 2->1 unless you blip the throttle to match the revs for an instant so it slides in.

This leads me to believe that even when the clutch is fully depressed, that 1st gear and whatever it engages to (holes in my knowledge showing :)) are not fully seperated.

For this reason...I believe that while sitting at a light w/the shifter in 1st and the clutch in...that the gear is somewhat engaged and the syncros may be wearing a tad. IMO I don't think this is going to produce a sizeable amount of wear even over the life of the car, but I have heard otherwise from some.

Does anyone KNOW the answer to this??? So far I've just given you a somewhat educated guess.

-Mike

Well guys, I thank you all for taking the time to confuse me :lol: j/k. No really though, I do thank you for taking the time to post a reply to my question.

I will continue to use engine breaking while coming to a stop.... as long as I'm not droping the clutch I feel it should have a glorious life. Hell, even if it doesn't, I'll just pop in a race clutch :)

Thanks again guys.

Blue

I always downshift to slow. I know some people put it in neutral and coast to a stop but I consider this dangerous. You should always be in a gear where you can step on the gas and react whenever the car is moving. I've been driving Japanese sports cars for 15 years and have never bought a transmision. Never bought a clutch till 100,000+

It's important to differentiate between "Downshifting to Stop" and "Downshifting to slow for a turn".

I do both, and I'm still working on proper Hell+Toe Downshifintg.

If you are not in gear, the AWD system cannot work! Trust me, I learned this on a canyon drive when I shifted during a turn. Thankfully there was a wide enough area nothing bad happened. If you are turning you should be in gear so AWD can work and pull you around the corner.

If you are slowing down in slippery conditions, if your in neutral, the AWD cannot work, your depending entirely on the ABS.

...Obviously this information applies only to the manual transmission, but since that is what this thread is about in the first place, I felt it was implied...

driving stick is sort of an evolution...first i started off slipping the clutch while downshifting (and i thought i was pretty cool - someone told me about this) - then i got more into serious driving and learned to heal-toe (i had to buy pedals for my civic, the stock ones were too far apart, the wrx's look okay though).
so i practiced that and got better and better, now i do it all the time. every stop ever turn, just brake, clutch, blip throttle while moving stick, let clutch out, and so on. leaving it in neutral doesn't seem like a good idea (as was pointed out by someone else) because u are left looking for a gear if you need to GO!
after learning to match revs really well and heal-toe, i taught myself to double clutch, but u don't really need to do this with today's synchro's. and its overkill for street driving. double clutching is good for autocross though when you shift from second to first before a turn, makes it easier to get the stick into first. anyways, just slipping the clutch to downshift will add to the wear on your clutch, much more efficient to learn to match revs with heal/toe (and it sounds way cooler too =)
note> its easier to be smooth while downshifting during 'spirited' driving then at standard street speeds, but once you get used to it u can be really smooth..
wish i had a WRX... =)

oh > and to the guy who had the bad experience during a shift on a turn...u didn't lose control because you 'weren't in gear' (not exactly) - its because during a turn the car is in an equilibrium (sp?) - a balance. you have a 100% adhesion of your tires to use up with a combination of turning and braking (or gas). when you entered a turn the lateral forces on the car (pushing you sideways) were being offset by the forward momentum from the power to the wheels (pushing you forwards). when you tried to shift you cut the power to the wheels and now the lateral forces were greater then your forward ..forces. (haha). and you lost control. if you have some room (abandoned parking lot at night), take your car and go into a constant turn (a circle), make it relatively tight, don't have to be going TOO fast, kepe the gas even, your car is balanced, now let off the gas suddenly and watch what happens - your ass end will swing out on you.

i should point out that Heal-Toe and revmatching is not to help you brake (not nowadays anyways, we have awesome brakes) - its to prepare your car for the exit of a corner (if you are going in 3rd gear towards a corner you have to be in 2nd gear to exit out of with any power, you must downshift at somepoint, the best way is to match your revs while you brake, then get on the gas right away to exit in 2nd gear.).
but it does have the nice side-effect of not having to brake so much on the street, and it won't hurt your tranny. =)

i'll shutup now.

I never used to downshift while slowing down until I got a motorcycle - now it's kind of habit to do it my car as well. I agree with the consensus that if you do it smoothly at moderate engine revs your drivetrain should be no worse for wear.
As for keeping your car in 1st at a light with the clutch in, I've heard it wears out the throw out bearing of your clutch faster. I personally have no problem at a stop getting the car in first and motivating the heck out of there if I think somebody (a cell-phone gabbin, SUB drivin' soccer mom:lol: ) is about to hit me. I've had to do it a couple of times (not yet in the WRX, though).
I hope this adds to the confusion of how to properly operate a standard transmission!:lol: :lol: :lol:

Why do some of you think you need to double clutch? Must be that stupid effect from the fast and the furious movie trickling down. Hellooooooo, the transmission is of modern design and has syncros! Double clutching is for sissies, shift the freakin' car like a man. I have never, ever once had a problem getting the transmission to upshift or downshift, even into first. And no, I haven't grinded any gears and no I am not abusive to the car. And there's nothing wrong with downshifting as you are slowing. It would drive me nuts to coast in neutral to a stop. I don't think it's safe either, I'd hate to be left out of gear when I need to avoid something or power out of a skid. You won't put that much additional wear on the clutch, if any. My wife drives like that, coasting as she slows, I can't stand to be a passenger when she drives.

I want to clarify that yes, in a race car double clutching is sometimes preferred, but in a street car? C'mon.:rolleyes:

Originally posted by SleeperWRX
Ummm folks???
How did this become a discussion?

A)If you know how to double clutch (or heel/toe if you're a rockstar)....

then do that to downshift. If done properly there is no wear to any drivetrain components. This will get you in a lower gear which will slow the car down more. Continue downshifting this way as needed to slow the car as quickly as you want. Then put the clutch in before you come to a stop.

B)If you do NOT know how to double clutch...

Learn...
OR
Leave the car in gear as one member suggested until you are about to stop, then put the clutch in before you stall your scooby.



While I agree with the importance of learning to heel/toe - i believe the question was not *how* do you downshift, but rather *do* you downshift to slow the car or do you just use the brakes.

Originally posted by VTECboy

i should point out that Heal-Toe and revmatching is not to help you brake (not nowadays anyways, we have awesome brakes) - its to prepare your car for the exit of a corner (if you are going in 3rd gear towards a corner you have to be in 2nd gear to exit out of with any power, you must downshift at somepoint, the best way is to match your revs while you brake, then get on the gas right away to exit in 2nd gear.).



Exactly. Well put.

The only vehicals that you really don't want to downshift to slow down is an automatic. The automatic does not handle the downshifts as well.


I should point out that not only does the auto wrx downshift while going up steep inclines, it will do so going down them as well in order to engine brake. Also whenever I'm braking to a stop, the car will downshift to help braking.

So, I assume it must be an accepted technique.

i downshift all the time. i rev match. when driving agressively i down shift so i can pull out of a corner rather than bogging down in a higher gear. when driving without intention of agression, i down shift when i come to a stop light by simply leaving it in say 4th gear on a 40mph road and when it gets down to 1500 or 1000 rpm, and i'm about to stop, i simply go from 4th to 2nd and gently slip the clutch out, with just a dab of reving or no blip of the engine and go into 3rd, then about 5mph i disengage alltogether.

as far as going around a corner without any gear engaged, how crazy and unsafe is that!? man think about flying into a corner a little faster than you should and suddenly pushing the clutch in! the change in balance of the car is tremendous and can be dangerous. i practice keeping the car in gear all the time unless coasting a few yards to a stop. and as far as cornering goes, just try a highway on ramp and near threshold cornering speeds and then suddenly push in the clutch, the back end will swing out!

>If you are slowing down in slippery conditions, if your
>in neutral, the AWD cannot work, your depending
>entirely on the ABS.

Does the AWD system help keep the wheels from slipping while we decelarate the same way it does when we accelerate?

-Mark

Originally posted by Mambo Kid
One person mentioned putting the car into neutral while stopped at a light or intersection. I think this is a terrible idea. I have the car in first gear, foot on the clutch, one eye in the rear view mirror, and the other eye scanning right, left and ahead of me. I want to be ready to move out of the way when that preoccupied, cell-phone gabbing, SUV driving soccer Mom or sales guy comes barrelling my way. With the car in neutral, you're a sitting duck.

I have 2-3 minute waits at some lights in my commute and loads of traffic... And my clutch takes ALOT of effort to keep down (ive tried RS's and WRX's and they are sooo much softer than my clutch pedal)

So I have plenty of time to shift into gear on time, and I'm a pro at keeping track of who goes when at a light and when my turn is coming :)

What your daddy taught you was wrong (and dangerous).

You should NEVER coast a car in neutral. It's just plain dangerous. If you must coast and don't like to engine brake, depress the clutch.

Consider: what if you become involved in a potentially dangerous situation from which you can only escape by guiding the car in another direction under power? With the car in neutral, you don't have this option.

Coasting in neutral is dangerous.

Originally posted by AVATAR-X



I should point out that not only does the auto wrx downshift while going up steep inclines, it will do so going down them as well in order to engine brake. Also whenever I'm braking to a stop, the car will downshift to help braking.

So, I assume it must be an accepted technique.


What was ment by that was manualy shifting out of drive into 1st gear. Most autos will not drop down into first gear untill the vehical has slowed down to a safe speed. I am not sure on the details of it but I have heard that it can ruin the transmission over time. While the car is in drive if it down shifts it is doing it to optomize the engine tourqe and isn't forcing it down into the lower gear. If I have my info on this wrong feel free to tell me, I don't have an overwhelming knowledge of car.

Automatic transmissions downshift through all gears under braking. You can witness this by watching the tachometer as you decelerate. They are typically tuned for optimal smoothness, so the shifts occur at sufficiently low RPMs and slow enough that they are not detectable in the vehicle deceleration rate. Some of the newer transmission control systems incorporate fuzzy logic, learning driver behavior and making better use of engine braking for spirited driving styles. Some also make more use of engine braking for improved brake lining life.

Engine braking uses the engine's compression and flow resistance (like an air pump) to slow the vehicle. The rotational inertia effect is not dissipative.

When operating a manual transmission, it is desirable for high speed turn execution to select a gear prior to entering the turn which provides the appropriate engine RPM for the turn exit.

When braking in a straight line approaching a controlled intersection such as a red light or stop sign, it is not necessary to row down through the gears of a manual transmission (as an automatic transmission does). An automatic needs to do this because it has no predictive capability as to when the slowing will end, where as the driver of a manual transmission can see that he will be coming to a complete stop and there is no need to select intermediate gears. Some improvement in brake lining life could be obtained, but this would be at the expense of some clutch lining life, although these effects are small as long as the shifts are conducted at lower RPMs.

Double clutching spins-up the transmission intermediate shaft which is critical in a racing transmission which has no syncros.

As far as shifting in a turn goes, any mid-turn change in tractive effort will disrupt handling balance. AWD does indeed provide a stabilizing effect on the vehicle when compared to 2WD. Porsche and Lamborghini use AWD systems not to make thier products faster, but to make them easier to drive.

A couple of the above posts imply that using AWD and compression or engine braking in slick conditions is better than relying on the ABS. I beg to differ. I use engine braking under normal conditions but when the roads are slick I rely on ABS.

It is not always good to relly on ABS in slipery condition. In my last car I had the car's computer turn the ABS off multiple times after the ABS had been engauged for a long time or after exsesive tire spin going up hills. After that you can step on the brakes as hard as you want without the ABS coming on letting the tires lock up.

Just like VTecBoy, I slowly learn my way up. First I was learning to rev match with the clutch down, then double clutch and now I'm doing heel&toe all the time. I tend to do h&t at turns and simple rev match towards a stop. When you rev match your engine the clutch or trany is not going to wear at all. The extra few nanometer of brake pad saved is a nice bonus as well.
P.S. have to admit I do the evil coasting down a slow city road to save gas (california gas) ... :rolleyes:

plus it just sounds cool (the blipping of the throttle)...=P
...not to mention how good it feels to row down the gears with perfect precision.

i'm so used to h&t i even do it when doing an emergency stop.
last winter it was a very slushy night and i was going faster then i should have been on a deserted stretch of road. (i was doing 90 km/h, not too bad but faster then i should have been givin the conditions of the roads.) wouldn't ya know it, a deer steps out not too far ahead, had to slam the breaks, the abs is going nuts, and out of instinct i rowed right down through the gears, (starting from fifth). bambi lived. =) dunno if the downshifting helped, but i suprised myself with the reflex.

anyways... yata yata yata.
driving should be fun, thats why you guys bought wrx's right? might as well do everything RIGHT to make it the most fun it can be (not to mention having the car last as long as possible). if you can't - definately learn to heal+toe/match your revs. its very satisfying. and if you ever find yourself going to the track(road course or even autocross) you will be very glad you know how.

Just brake with the brake pedal, but DO downshift as you slow down, so you are in the right gear as the speeds go down, coasting in neutral your car can actually GAIN speed...as opposed to coasting down in a gear.... but i agree, i dont downshift to use the force of the drivetrain to slow me..

Engine breaking is something I've always practiced and continue to do today with my WRX.

Done properly, i.e., don't downshift such that the lower gear would be at 6000rpm, you should always be at a point in the rev-range that allows you to accelerate briskly, either because you're preparing to enter a corner and want to be in the correct gear for the exit, or just for safety's sake when slowing for a stop light, or something.

Other than my last car, a Honda Accord, which was auto, all my cars have had manual transmission. I never had transmission problems, and my brake pads last for a long time.

If you don't want to down-shift, DO follow the advice of others here and stay in gear, any gear. Sticking your car in neutral is a BAD idea and not at all safe.

Cheers!
Bradus

In normal driving I just hit the clutch, shift to neutral, and brake to stop or turn. However if the traction situation is questionable such as a loose surface, water, uneven terrain, or just driving agressively, I'll drop it into a gear that'll put the engine up to 3500-4000 RPM right before I start turning so I can exert some control over the vehicle if it starts to slide. Otherwise IMHO downshifting is unnecessary. I know it's been said that engine braking won't hurt anything but I still don't see what the point of doing it is in daily driving besides habit, practice, or wanting to sound cool. I don't think you can make a blanket statement one way or another, just learn to do it both ways and be flexible.
BUT.... If you want to downshift for control reasons please make sure you know what you're doing. If you get scared and lift throttle as it breaks loose, you'll get some nasty oversteer and may end up spending some time with your insurance agent.

BTW: Downshifting when traction is questionable is also good advice for RWD and FWD cars too, BUT, I EMPHASIZE, only if you're familiar with the balance/control of the vehicle.

I primarily downshift as preparation for accelerating again. Whether it is to blast out of a corner, pass somebody, or just because I would rather be in the power band.

But engine braking can be a wonderful thing. Whenever I have to stop FAST, I will downshift. You have to do it whenever you stop fast, so that the one time when you panic brake - instinct won't fail you.

yes, I use engine braking, but only in third gear. Higer gears don't really engine brake, lower gears aren't needed. If I am below 50-40mph, I use brakes.

The only time you really NEED to use engine braking is going down long hills. You can still wear out/loose brakes on long inclines, even today's brakes.

Automatic transmissions downshift through all gears under braking. You can witness this by watching the tachometer as you decelerate

I love it - they give you a tach in an automatic but NO FRIGGIN BOOT GUAGE IN A TURBO CAR?!?

I think he meant coasting to a stop type of driving, not turning at a radius or running down the mountain. Usually, if I see a stop light.. I will just let the car coast in its current gear till 1 - 1.5k rpm or so, and switch into neutral.

About going down the mountain/hill , the engine seems to strain a lot to keep the car from going fast (if I just leave it in gear and let it roll down the hill.) I don't think you are suppose to engine brake for an extended period of time, say.. going down the mountain for 10-15 mins. But like other people said, you have no control over the car when it is in neutral.