Toyota said no... Then okay
 

I contacted Toyota about coasting in N with my Auto in my Yaris. Did this by email and got a response about 3weeks later saying "we do not recommend you do this"

well, duh thats the answer i expected, so i called up corporate with my question in thier data banks (thier system is scary efficient) and asked the question again. The person on the phone asked me to hold then after about 5 minutes go back on the line and said that it was a 'safety' issue if acceleration was demaded and also that the mileage increase was negligable.

I politely disagreed on the second point, then asked specifically "is there any mechanical problems that can arise from coasting in N" and she said "NO"

So, as far as I take that; Toyota said that my auto coasting wont hurt anything mechanically, just that i can't accelerate while in N....

hmmm, guess i'll keep the coasting going!

Nice work!

Next, I'd ask them if there are any mechanical consequences of coasting in N with the engine OFF. To avoid the TSK TSK factor, you could phrase it in the form of a towing question. :)

PS - I'd specify: short distances.

i have an 07 yaris Manual. So it won't hurt the engine at all if I shut it down, coast and start it up *fas*. I know you can start a manual that way but in effects of transmission, this would not hurt one bit, correct?

It won't hurt the manual transmission to coast, no.

If you re-start the engine using the clutch, I wouldn't say you're hurting it, unless your technique is really rough. There would of course be some additional clutch wear.

BTW, welcome to GS sam07yaris. :)

Feel free to tell us a bit about yourself in the Introduce Yourself forum.

I am glad they said it would not hurt it, but I was going to do it during my warranty and let them prove that is what broke it if it came down to it. Worst case I could sell one of the 4 vehicles sitting in the yard to get the trans fixed. But I really do not believe anything bad will happen to it, and neither does the guy who has replaced, rebuilt any trans or clutch in my family for the last 10 years. None of us has ever ruined one but have bought a few that way and he is a pretty straight shooter.

Just keep in mind that each time you start your engine you cause wear to the piston rings that have no lubrication when they sit at 0 rpm - no oil film holding them off the cylinder walls. In an auto transmission coasting in neutral I would think would be ok although I wonder how many gears are turning connected to the output shaft(s). I would not recommend turning off the engine as it provides lubrication to the moving parts in the transmission and have been told that the seals also are lubricated by the oil flowing from the engine pumping the torque converter. I suppose a diagram of the tranny will show this if we can find one. Also keep in mind that the computer in my Scion xB running the gauges and engine will not produce a signal to the Scangauge if the engine is not turning over even if the key is turned on - same in a Yaris I think.

I am not doing engine off. I am perfectly happy with the N results. BIG HILLS :)

so, why would it have been considered bad in the past? What was the theory? I'm interesting.

If you mean why did we need service? We have bought used cars exclusively and they had issues when we bought them, truck had a bad trans we got the truck for next to nothing. 94 Vette needed a clutch we knew it on the test drive offered $3500 less and bought it. Between my wife, my father, mother and sister we currently own 12 vehicles. In the last 10 years that number is probably a collective 40-50.

If you mean why it would be bad to coast in N in an automatic even with the engine on, it is as hotly contested on the web as the value/use of synthetic oil. People have LOTS of opinions.

Sorry to answer this way I wasn;t sure exactly what you were asking.

no no, answering the way you did is great. Answers more questions, even if they aren't mine. And mine was the second one, thanks.

I wont shut the engine off, just too darn scared to. But going in neutral for 10-13 miles at around 70-80mph is way cooler than putting my foot on the gas just to stay at 60-65!!!

getting over the fear, is one of the most important steps to gaining superior FE. Not only you have to get over the fear without power delievery, you also have to get over the fear of pissing off other motorists. Once you managed to overcome these two factors, you'll look back and are glad its you vs the whole driving world.

Bring it on.

Hi all

It doesnt hurt manual transmisions to coast in N bacuase they are lubricated by splash feed.

In an automatic trans vehicle the parts are cooled by the trans fluid and only when the engine is running.
That is why they say dont tow an auto car for more than a few miles and keep the speeds very low.
This is with the engine OFF tho.

Now just kicking it into N while your coasting up to a set of lights or down a hill now and again shouldnt do any measurable damage , but it is likely that over the whole life of the car the transmsion would have run hotter , which may translate into it dying earlier.

I WOULD use N , but I wouldnt recomend it., and shutting the engine OFF while coasting really is nuts under any condition.
You lose power steeering and brakes and with an auto you lose the ability to bump start it quickly if your need to.

I wouldnt even turn OFF and coast with a manual tran'd car.

nah, only those who never tried it says that. Those who I have interacted with it and has some experience with it little or a lot, agrees 100% that there are safe situations where you can coast with the engine off and still keep up with the guy on the left running his engine at 2000 rpm.

when your car is moving at a certain velocity, then power steering really isn't needed since there is very little reisistance between the wheels and the steering. When speed drops really low like 5 mph or something then the tires are going to have a lot of grip and friction is really going to work those arms of yours! Well my car 2400 pounds I can live without power steering however I'm noob under the hood so I don't touch that garbage. I remember a camry 3000 pounds easy to steer when at speed, but when trying to coast into a parking lot boy I don't want to do that again!

You still have vaccume in your brakes after your engine is off, by the time your vaccume runs out my engine is on again anyways. And since your coasting with the engine off your trying to get a lot of distance without it, so if your braking a lot then you have chosen a very bad time to Codfish. Usually when I have to brake my engine is on again anyways because something out of the odinary has caused me to slow down (since killed my engine because I KNEW that I was going to coast and be able to maintain my speed for a long time) so I need to pick up speed before i kill the engine again.

As for codfishing under an auto, Master Wayne (One of America's best hypermilers) has key on/off good lord how many times on his Honda Accord 4cylinder auto tranny. over 60000 miles and he just replaced his first battery, and this is the guy who gets over 47 mpg lifetime on his car! For the amount of gas that he saved, I think 60000 miles per battery change is a okay by me! And nope he hasn't replace the starter once its still strong by his words.

When your engine is hot and has reached optimal temperature, it doesn't take much at all to start the engine. An cold engine needs maybe a few seconds of cranking to start the engine, but on a hot engine that cranking is reduced to like 1/2 a second and the engine is back alive already. So in the process you used less energy to start the engine again.


Cold starts are the worse, if anyone knows how much energy it needs to start a starter on a cold engine and then the difference on a hot engine please give me data! Thank you!

codfish: Coasting on demand something something oh my... i forgot! I like the FAS term better ;)

Hi philmcneal

Well ,..I dont care one bit about Master Wayne.

By the time a person with an auto trans , coasting , with engine off in N has reacted to that little red headed girl that just rode out in front on her bike youve JUST SQUISHED HER !.

And I dont care about how many starts a guy can get on his battery , the fact is there , the reaction times to restart an Auto is TOO long.

Any one that adopts this driving technique must be bonkers., and if there is a fatality from using this method , you will not be able to talk your way out of it in court - you will go to jail.

That is why in many places even coasting along ion N is against the law.

I'me all for increasing FE , but ime not crak't in the head.

I disagree and think it depends on vehicle. For instance, there's plenty of manifold pressure left with the engine off and tranny in N to slam on the brakes just as well as if it were on, but only for a short period, which is exactly what an emergency is. Otoh, if you're braking consistently, then you'll run outa vacuum quick and that's definitely dangerous. The same probably applies to power steering, with some systems being easier to man handle than others when the pump is off.... For example, I've driven two smallish cars with the PS out, and they were just as easy to turn as a chevy van with no PS, but there's no way I would kill PS if the vehicle weighs over ~3-4k lbs and is fwd.
So, if there's clear road, light traffic, and low speed driving ahead, I don't think coasting in N in an auto is any more dangerous than driving in gear, provided you understand how the car behaves and can respond just as well during emergencies regardless of whether the engine is on or off.

Hiya omgwtfbyobbq

My comment was negative against having the engine switched OFF , and in N in an auto trans car.
But your comment seemed to show that you thought the engine was still running.(which is a totaly different and much better situation)

The reasons behind this are;
When an engine is turned OFF you will have 1 or 2 power assisted braking applications available , BUT , for any advantage to FE gained by turning the engine OFF it must be OFF for some time., and this is the problem.
If a driver is assuming that he will have power assist on his brakes 30 seconds or a minute after turn off he should investaigate it further.
Vacuum presure will often be gone in less than a minute of shutting the engine off.
One way valves , boosters and simple clamp hose connections will bleed vacuum.
This means no power assist.

To get a light pedal many manufacturers use small brake pad area but with a high level of assist.
In normal driving they seem quite OK , but lose vac and even a small cars brake pedal can require substantial foot presure to pull it up.

In the case of an auto car in N with the engine OFF . the driver MUST key restart the car and WAIT before vac comes up , power steering will come back instantly tho.

From reading our drivers educations book we should have learnt about the distances added to braking due to delays in our reaction times.
Adding this extra time (from restarating the car and witing for power assist) adds to the time before we can have an effective reaction time.
This time adds to the distance covered before we can stop.

In an emergency we want to stop in the shortest distance and fumbling around for the key and trying to retart isnt in any way smart.

Some might think it is safe , but I wouldnt ride with anyone that does it.

Personally, I shut-off for ~a two and a quarter mile leg at ~40mph and notice no significant difference in braking at the end of my run. So, the rate at which vacuum bleads is probably proportional to how long a specific engine/brake booster system has been off, and I suppose the best bet would be to run some experiments to determine the amount of time that can be spent coasting while still allowing the driver to effectively stop the car.

The only other nit I have to pick is with your characterization of a driver attempting to start the car in an emergency. If there really is an emergency then the driver won't have time to start the car, they'll either brake, swerve, or do some combination of both. I've never seen, personally head of, or been in a situation where accident avoidance required the use of the throttle. I suppose the driver has to turn on the engine at some point, but so long as they don't do anything weird like stare at the key, and keep their eyes on the road they should be able to respond exactly like they would if the car was on and in gear because vacuum hasn't degraded to the point where it impairs the ability of the driver to stop the car. If they let the vacuum degrade to the point where they can't stop effectively, then they're not being safe, but provided proper precautions are in place, imle coasting in N can be just as safe as driving in gear, and net a pretty big increase in mpg.

Of course, each car is different, so YMMV, but like theclencher said

Have an animal run out in front of you and suddenly that power steering would be really handy - also engine off shuts down the odometer and abs brakes and in my xB stability control also. Plus it does take some time for the engine to warm up and cooling it down along with the exhost o2 sensors and cat will increase emmissions no? Brakes should hold vacuum for some time but when they go it will take getting used to plus reaching for the key while pressing etc. Good point on the auto tranny cooling too! I'm gonna just keep it in neutral with engine on thank you very much. Oh yeah and then there is the power windows too.

I've never driven a car where this is the case (loss of vacuum reserve in such a short time without using the brakes). To me, a loss that quick suggests a problem with the system. (The vacuum reserve is after all a safety feature.)

My 8 year-old econobox retains strong vaccum assist for a couple of brake applications several hours after stopping the engine, and partial assist for one application even after being parked for over 24 hours.

I agree that every driver should know his/her car though.

Ive been coasting engine off since I was taught at 6 years of age. I guess I was luckey in the fact my father belived in starting us young in all types of driving. With focus on skills.

I currenty, at will coast my 2000 5MT Ranger, 2005 Accord 5AT and my 2006 Civic 5MT. I have coasted, ICE off every car Ive ever owned and many of my friends and familys cars and trucks.

As for safety? Get some skills. My cars hold vacume very well for the brakes. Power steering and the lack of it has never hindered me in the ablity to control my cars or trucks. I have the brawn to muscle my cars very fast. Now the wife dosent so she dosent FAS. Thats a limit put on her by her small size and muscle distro. And general lack of skill and for thought.

I have never worn out or broken a tranny. Never!!! AT or MT. A nice thing about older AT trannies in the old days was they would restart the ICE if you were above 15 or so mph. Have the ignition on and drop them into drive. Ive had several old power glides and turbo 300's with some old Ford units that would do this with no ill effect.

Ive FAS'd every motorcycle Ive ever owned also. And I intend to FAS my new Harley when I pull the trigger and get it.

As for the jail and law stuff. Go get on cell phone users. There more danger to the motoring public than drunks.

Your fears are unfounded. LOLOLOLOLOL

OO I would also put Waynes over all driving skills up against yours and alot of other folks any day of the week.

honestly, HONESTLY, there are only 2 reasons I don't shut the car off to coast: #1 is because I truly believe that it isn't good for your ECU. ON/OFF/ON/OFF/ON/OFF....I mean, c'mon. Isn't that how Sh#@ breaks?! Eh, the #2 reason is because I think every other driver on the road will think I'm screwy. If the car next to you is OFF, that car has usually stalled. As it is, when I'm approaching my parking spot at work and I turn my car off 100 feet or so before I reach my spot (coasting) I get the feeling people think "what the hell is wrong with him" or "is it really that bad...are the gas prices killing you?". But really, that's just me. I'm funny like that.

Yeah. What he said. I have NEVER run out of vacuum even after coasting for over a mile, I have NEVER had uneven tire wear, and I have NEVER broken a tranny. Oh, and I've NEVER burned out an ECU or worn out an ignition switch. Skills are very necessary. If you don't have the proper skills, then no, don't coast with the engine off.

You don't necessarily have to shut the key off to kill the motor.

My ECU is always ON because I stop the engine with an coil pickup interrupt switch I installed. The power to the ECU is constant.

After next week when I pick up my car, it will have an injector kill switch.

TBI, Larry?

I'm not exactly sure what you mean but I'll take a stab at it. My injector kill switch should work on TBI as well. You would be doing the same thing but would only have one wire to splice into instead of the 4 that I had.

To answer some questions that were never asked...

Are you sure you have to tap into 4 wires? most fuel injectors work off of seprated ground for control, but a shared 12v switched source that it split through a power distribution block. On all of my cars, an injector cut is as simple as wiring these 4 wires (or 8) into a switch, then connecting it to a 12v switched source.

Shutting off the motor on a motorcycle is a BAD idea, the gearbox in these is not designed to be coasted in, you shouldn't hold the clutch in vary long at all, it's really not good for your transmission.

BTW, i've engine off coasted (not sure of hte letters for this) many times in my 4044lb Lincoln Towncar. It's vacuum reserve is the size of a coffee can, so the brakes still work okay after i coast UP my driveway haha. The no powersteering is difficult, I'm more afraid i'm going to break something the steering wheel feels so flimsy :S

On my other car, it has no powersteering, and have never had a problem with this, I actually prefer it on light cars, better feel for the road.

I would like this information very much! An injector kill switch is my next mod. I'm going to mount it on the gear stick with overide switches to prevent my wife from hitting it.

I was thinking about it, probobly one of them spinny ones, right behind the gas tank :D