Toyota said no... Then okay

[philmcneal]

I wont shut the engine off, just too darn scared to.

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.

[onegammyleg]

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.

[philmcneal]

I WOULD use N , but I wouldnt recomend it., and shutting the engine OFF while coasting really is nuts under any condition.

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.

You lose power steeering and brakes and with an auto you lose the ability to bump start it quickly if your need to.

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

[onegammyleg]

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.

[omgwtfbyobbq]

Originally Posted by onegammyleg

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 !

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.

[onegammyleg]

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.

[omgwtfbyobbq]

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

Originally Posted by theclencher

I'll tell you something about safety: the biggest piece of safety equipment is on top of people's necks, inbetween their ears.

[JanGeo]

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.

[MetroMPG]

Originally Posted by onegammyleg

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.

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.

[psyshack]

Originally Posted by onegammyleg

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.

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.