EOC (engine of coast) tips?

[lunarhighway]

EOC tips

I recently tried to use engine of coasting on a more regular basis after a very depressing previous tank. I (finally) filled up again this morning and the results are impressive. roughly a 10% improvement in FE compared to the average on my last 4 tanks. all this without seriously altering my driving speed (I try not to drop to far below the speed limit or disturb the traffic flow)
I've also made a point of shutting of the engine when stopping at a redlight

I'm still learning this technique which I got from this site so I'm wondering if any "veterans" could give me some advice.
I'd like to draw up some sort of "EOC manual"

I'm also concerned about the downsides to this technique such are engine wear etc... extensive wear to the transmission might eliminate this benefit from an economical point of view

Here are some of my experiences; feedback or advice are welcome:
My car has a 4 speed manual transmission.I found that the 4th gear is the best for "bump" or clutch starts even when my speed is lower than when I'd usually use 4th gear. Also applying NO throttle when releasing the clutch seems to work smoother. Lower gears seem to be bumpy and sometimes results in screeching noises which I think come from the clutch and are not a good sign.

This technique has led me to sometimes UPSHIFT when slowing down, briefly releasing the clutch to start the engine again, en than quickly downshift sometimes even 2 gears.On some occasions this went remarkably smooth and natural,but sometimes things get a little bumpy.

Shutting of the engine however will leave me brieflie without breaklights and direction indicators, as soon as the engine stops I turn the contact back on.
but sometimes i have to leave of just a sec so the engine will not fire again.
on some occasions traffic behind me prevented me from safely turning of the engine. so i'm considdering making one or multiple buttons to start stop the engine, anyone already done this?

Since this is the first real improvement I made in FE since joining this site I'm quite exited so I hope I haven't repeated of combined to many questions in this one post.

[Peakster]

My general rule of thumb for EOCs is if I'm not applying throttle for within the next 5 seconds, the engine goes off. As soon as I see a traffic light turn yellow in the near distance or starting a decline, It's virtually automatic for me to turn off the engine.

Sometimes I do run into situations where I turn off the engine and the light turns green 2 seconds after. In those cases, I still wait until the ScanGuage goes blank before I bump start again (that way I know the SG will come back on when I bump start, and it just forces me to fulfill my 5 second rule).

[lunarhighway]

I recently heard that engine of coasting will cause extensive wear to transmission due to some bearings not being lubricated with the engine turned off.is this true and if so how bad is this? i still need to look into the mechanics of my car to see how things are arranged there but i'm not looking forward to wrecking my transmission somehow...it might be due to paranoia on my part but i kind of get the feeling i can hear more "squeaking" as from a worn bareing coming from "somewhere down there" it's an old car there's lots of things rattling all the time without there being any problem so it's not alarming or nesesary related, but it would be a pity if things turned out to be like that because i did manage to save 10% of fuel by using a lot of EOC... and it's nice to roll around at considerable speeds without any power being used.

it's quite cool to turn of the engine behind the last curve in the road and just coast only the parking lot and into a parking space.

does anyone know of bad(long term) effects of EOC?

[diamondlarry]

I've been using EOC for a few years now on a few vehicles and haven't had anything bad happen to a transmission. They were all 5-speed manuals. There is a guy in northern IL that has been using EOC heavily in an automatic Honda Accord with no problems either. Also, Saturn auto's are one of the few that can be towed without damage so I would assume that they would be unharmed by EOC.

[omgwtfbyobbq]

Vehicles with manual trannys should be o.k. as well as automatics that have an oil pump driven off of the output shaft, but most newer automatics don't have this (just an oil pump driven by the engine), so engine off coasting may result in some bearings going w/o oil for some portion of the coast, which may result in an early rebuild.

[MetroMPG]

Originally Posted by lunarhighway

does anyone know of bad(long term) effects of EOC?

In a manual transmission, EOffC will result in more wear to the battery, clutch, starter and ignition switch (unless you wire in a kill switch).

Enough wear to be a concern? Hard to say. Depends on the vehicle & how much it's done, I suppose.

I do a lot of EOffC. Ask me in 5 years if it was worth it.

[GasSavers_Bruce]

Originally Posted by Peakster

Sometimes I do run into situations where I turn off the engine and the light turns green 2 seconds after.

If I'm EOC'ing in heavy traffic, as when coming up behind traffic lined up for a red signal, I'll usually wait until the car ahead starts accelerating away from me before I start the car (when I'm moving, of course). A lot of times I'll come up behind others at a light that's just turned green, they'll start moving and then brake anyway because they're tailgating someone who's shifting gears.

[landspeed]

In the UK, engine-off coasting makes sense, with petrol/gas costing US$6.60 per US gallon .

Engine wear is the most 'scary' outcome of this; what I tend to do is use 5th gear to bump start it, at end speed down to 15mph. Down to 10mph I use 4th, and below that I would leave the engine running instead. After bump-starting it, I wait about 3 seconds, give it a slight rev to 1500rpm gently, then drive as normal (being gentle for the first few seconds). The logic is that, when stopped, there is no oil at the cylinder head or at the big end bearings. After starting, leaving the engine idling lets oil get to the cylinder head etc. Then, then little rev makes sure the oil has got to the big end / main bearings, before driving away.

The big-end bearings 'float' on a layer of pressurised engine oil (when the engine is running), and when restarting, they make contact and wear away. If you bump-start and immediately apply the throttle, then you will be putting a lot of power through these bearings, when they are still dry, which will dramatically reduce their lifespan. When these bearings do go, they start to rattle (for many miles), then a con-rod goes and pokes through the side of the engine, and almost always the head, block, crank, and everything else is a write-off.

Youtube - worn big end bearing - will need crank regrind, conrod regrind, new bearings all round : http://www.youtube.com/watch?v=qj7jLA-W91Y

This video has lots of silly comments on youtube, but shows what happens when a conrod snaps: http://www.youtube.com/watch?v=XI_gNQLmTM0
http://www.youtube.com/watch?v=lzif078Pn2E

Anyway, a bit off-topic, but interesting nonetheless, I think

[omgwtfbyobbq]

Originally Posted by landspeed

The big-end bearings 'float' on a layer of pressurised engine oil (when the engine is running), and when restarting, they make contact and wear away. If you bump-start and immediately apply the throttle, then you will be putting a lot of power through these bearings, when they are still dry, which will dramatically reduce their lifespan. When these bearings do go, they start to rattle (for many miles), then a con-rod goes and pokes through the side of the engine, and almost always the head, block, crank, and everything else is a write-off.

Why not invest in an electric preluber? Combined with a block heater, the driver may see great mileage as well as longer than average lifespan.

[lunarhighway]

mmm

thanks for all the comments..
yesterday i found that after i shut my engine of my windscreen wipers where running very slowly...i've also been having trouble starting lately.... seems like the battery is not fully charged wich would be logic since all that EOC has not been charging the battery, yet wipers and headlights where on most of the time. this is of course the clever thing with hybrids, that they can charge with the engine off.

seems that appart from engine wear i can't use EOC as much as i'd like to
i thing my battery might recharge if i drive normalyfor a while, but if it turns out to be dead i might considder replacing it with something more suited to my intended drivestyle.

this week i'll be trying some EOnC but i'm affraight the results won't be all that exciting.

after about 10 days if EOff i'm absolutely convinced that that it has great potential,(10% improvement in FE ) but i'm worried i can't use that full potential because it might quickly wear out my car... still i'd like to integrate this technique into my drivestyle as much as possible