EOC (engine of coast) tips? - Page 2 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 02-05-2008, 02:38 PM   #11
Registered Member
 
guest001's Avatar
 
Join Date: Feb 2008
Posts: 198
Country: United States
My first thought on this technique was accelerated wear of the starter.

I was really excited about this technique cause it sounds like it has lots of potential more then a lot of things I've read. Esp. if where talking about long strecthes of road or hills. Unfortunately I have a turbo on my car and shutting off the engine like this is a no, no on turbocharged vehicles.

well, I know that oil is multiviscosity so the oil can more easily flow through the engine when its cold. but that's just when its cold and it makes oil thicker. I'm sure oil would have no problem doing this with the car at operating temp. you always hear not letting the car warm up before you drive accelerates wears. but where talking about it being warm.

I think the result would be worn out starter, batteries, etc. and not so much the engine. but thats not really an issue since that stuff is lifetime warrantied. and autoparts stores are really good about honoring there warranties on such items.
__________________

guest001 is offline   Reply With Quote
Old 02-05-2008, 03:56 PM   #12
Registered Member
 
Snax's Avatar
 
Join Date: Mar 2007
Posts: 758
Country: United States
First, let me alleviate some of your fears about hot turbos and shutdown: While you are technically correct that immediate shutdown can damage the bearings in the turbo, for the most part that only applies after heavy use. During normal easy commuting, there is not enough heat buildup in the turbine housing to damage the oil. After driving hard however, the turbine housing can be glowing hot. In other words, the amount of heat it must deal with goes up proportionally to the amount of loading. So if all you are doing is taking it easy on surface streets, the turbo is unlikely to be much warmer than if you were to just let it sit there idling. The only way to be sure however would be to measure it, so don't take my word for it.

Another thing worth noting is whether your turbo is water cooled or not. If it is water cooled, you have even less reason to worry. Convection through the cooling system will continue to provide a fresh flow of coolant even with the motor off, and this will keep bearing temps well below where the oil is damaged.

And the one last point worth noting is that synthetic oil is far more tolerant to heat. When dino oil cokes up, the synthetic hasn't even gotten close to it's breakdown temperature.

So in a nutshell, my view on EOCing with a turbo is that it's probably ok, so long as you aren't doing it on the highway or immediately after driving at high speed and or high load. But I'm not guaranteeing anything! :P

As for the extra wear, I don't think we are getting something for nothing here. It's a tradeoff no doubt.
__________________

__________________
LiberalImage.com

I think, therefore I doubt.
Snax is offline   Reply With Quote
Old 02-05-2008, 04:30 PM   #13
Registered Member
 
guest001's Avatar
 
Join Date: Feb 2008
Posts: 198
Country: United States
The turbo has the ability to be water cooled but It's not, cause of the extra lines and even more so cluttering of my engine bay (need to really work on cleaning up my engine bay). but it would be well worth doing.

a temp gauge on the turbo would be awesome :-) .

your probably right though cause it states in this book at it only take 1000 yards or 1 minute to cool down an a turbo after "high output use" . driving for mileage and doing 60 on the highway is definately not hight ouput use. it also doesn't say if your using synthetic or water cooled.
guest001 is offline   Reply With Quote
Old 02-06-2008, 06:58 AM   #14
Registered Member
 
Join Date: Jun 2007
Posts: 358
Country: United States
Send a message via MSN to baddog671
I EOC alot and its where I see all my FE gains. Currently being as cold as it is, my fe sucks, but soon as spring hits Im going to break my record of a 78mpg tank.
__________________
baddog671 is offline   Reply With Quote
Old 02-06-2008, 05:54 PM   #15
Registered Member
 
guest001's Avatar
 
Join Date: Feb 2008
Posts: 198
Country: United States
I dunno, I've been messing around with this a little. using it on my commutes. finding places where its actually worth it, etc. but my half a tank is looking pretty bad. I haven't really given it a whole tank. but the gas is going down pretty bad on almost a complete half tank.

Do some cars not respond well to this or is everybody else getting great mileage with this technique???
guest001 is offline   Reply With Quote
Old 02-09-2008, 04:14 PM   #16
Registered Member
 
Snax's Avatar
 
Join Date: Mar 2007
Posts: 758
Country: United States
Well to paraphrase something said in another thread, if you only spend 5% of your time EOC'ing, that only accounts for a saving of 5% at your lowest fuel consumption which isn't really a heck of allot. E.g.:

Assume your idle fuel consumption is .3 GPH, but you burn 1.5 GPH at 60 mph. In one hour, assuming you spend 5% of your time idling, your overall average consumption is .015 gallons at idle, plus 1.425 gallons at speed, for a total of 1.44 GPH. Converting that idle time to EOC time, it drops just the .015 gallons to 1.425, or 98.96% of your normal consumption.

So in this example for a car that could get as much as 40 mpg without EOC'ing, one might see as much as 40.4 mpg using EOC'ing just 5% of the time.

Obviously this oversimplifies the math, but there ya go. Factors that will skew the numbers better or worse are of course the percentage of EOC'ing, and the rate of fuel consumption at idle.

That said, I think there are better ways to save a gallon of fuel without the extra wear and tear - even though it took me until just now to really figure that one out. Certainly there are conditions however where EOC'ing can provide substantial gains in FE such as while descending a long grade, but around town on the flats, it's going to be minimal.
__________________

__________________
LiberalImage.com

I think, therefore I doubt.
Snax is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
More SMS Requests zbret Fuelly Web Support and Community News 16 02-03-2011 01:09 AM
Incorrect Milage Calcuatlion PatM Fuelly Web Support and Community News 4 07-17-2009 08:21 PM
State of the Union address touches on "oil addiction." Matt Timion General Discussion (Off-Topic) 31 02-06-2006 04:38 PM
A tidbit about IAT temps and resistance SVOboy General Fuel Topics 9 02-05-2006 01:06 PM
"active" aero grille slats on 06 civic concept MetroMPG General Fuel Topics 21 01-03-2006 01:02 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 12:22 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.