engine off and coast question
 

I have an 07 honda fit new to me. Since I found this site I've herd of this alot please elaborate.
How long does the engine have to be off and started back up:confused: to benefit over neutral idiling?
How viable is this technique saving gas over wearing out my electrical system. (At so can't gear start)

The gains are there, they are compounded after dozens and dozens of engine off coasting , you will save a negligible amount but it will add up and you can hypermile with it to get more gains. The technique defiantly works it`s just to much work for me..


I don't engine off coast because I don`t need to to get great gas mileage , I normally coast with engine On unless its a extremely long coast , like a 5 or 10km , I have a mountain Pass that I coast home from for over 10kms a couple times a month.

5+% possibly?

Agressive EOC and engine off at lights gave me massive gains on my MB100, over 15%.

BMW and Ford have auto stop start systems and quote 3 and 5 seconds as the break even period. I have auto stop start on my Fiat :) I won't buy another new car without it.

Most people will agree that starting a hot engine takes very little power and places minimal stress on the starting system, though it may be a good idea to add a solar panel to keep the battery fresh (which is what I did).

I bump started where possible though.

I just randomly did a google search for the cost of a 2007 Honda fit starter

it ranges between $50 (ebay) - $172 (remanufactured oem)

I've saved over $600 in fuel costs PER CAR / PER YEAR by hypermiling/ecomodding both my old Honda Del sol and Subaru wrx sti

Can your vehicle be flat towed?

Is your Fit an automatic or manual transmission? If it's the latter, then bump starting will save your starter. I would say 5 seconds is an absolute minimum. It would get too complicated to do it more often.

I would start EOC'ing at the *best* situations, and then add shorter times as you see fit. (No pun intended!)

He said AT.

If your vehicle can not be flat towed, I would not advise EOC.

I've been turning my engine off at stoplights in my truck for decades - literally decades. And now with the truck entering its 27th year, it's on its third starter. You might wear the starter a little faster than otherwise, but averaging nine years on one isn't bad either. And my truck's mileage is fantastic.

I would recommend shifting to neutral for coasts rather than coasting in gear. You would need to do some math to figure out where the break is, but I think the greater glide in neutral will more than offset the zero fuel use of the shorter glide with the tranny driving the engine. An engine control system will usually reduce the fuel feed to the engine in such a state to zero, but the engine drag pulls the vehicle speed down too quickly. The engine doesn't pull much gas just to idle, so the longer glide can deliver better results. Again: testing and math to know where the better results lie.

I've heard a break even point of 7 seconds... via this site. Make doubly sure your vehicle can be flat towed before you try this, and always do it in neutral only. Automatic transmissions are not generally made for that kind of stuff, whereas manuals have no problem (but also must be in neutral).