EOC and bad mpg...
 

Just a quick question for all of you talented hypermilers out there...

Has anyone else had bad mpg results from EOC in city driving?

It seems to me that when I kill the engine in neutral and coast up to a red light, wait until it turns green, start the engine and resume driving that I get dramatically worse mpg.

I've tried this on 2 different tanks of gas and tried to be consistent about which lights I pick and how far away from the light I am when I start the EOC. My last tank of gas was one of these that I tried EOC on and I only got 243 miles on 15 gallons of gas and this was based off the Trip Odo rather than my ScanGuage II. Also, this last tank had bad MPG to begin with as I posted in the Insturmentation forum earlier. My normal mileage on a tank is between 340 - 380 miles on 15 gallons.

I realize that my '97 Cavalier, 2.2L 4 Cyl, 4-Spd Auto isn't the best candidate for EOC especially since it has about 206,500 miles on it but I thought it was worth a try. It just seems like EOC is not a good choice for me.

Any and all advice is welcome and my thanks are freely given,

Jeff

Do you put the key back to "run" once you've shut it down? My trip odo does NOT increment in ACC, only in RUN. This could meant hat your mileage is not being reported.

Thats what killed my numbers at first. I have to turn my key back to 'run' in order to get credit for miles 'driven' while EOC-ing.

Same here. I realized that one day while driving downhill EOC. I don't do it much, but I realized my ODOMETER wasn't moving!!!!!! I turned the key back forward and they started going again. Great way to keep your mileage low for resale huh? :D ;)

LOL, same thing happened to me. I'll never get that 17 miles back...

BTW, if this is what's happening to you, then that means you did something like 100 miles with the key off. Good job!

The way a lot of folks deal with this losing the speed signal issue is to install a simple Kill Switch.

FYI, I've been tracking EOC with the latest mpguino version and so far Ive gone 3.46 miles, 2.75 of which were EOC (just around town testing)

Yeah, I put the key back into run to get the insturments back on when I try EoC. My ScanGuage never stays on for more than about 10 seconds with the engine off and the key in run so I figure it's not recording the distance traveled vs. fuel used at that point.

My trip odo and mileage odo record the distance that I go with the engine off but when I watch fuel economy per trip and get to the gas pump at the end of the week, I either see very little improvement or I see less mpg than what I think I should.

Right now it doesn't matter though as my car is in the shop with a dead alternator and probably a dead battery. It died Friday night on the way home from work.

Thanks for the info though, I do appreciate it.

Jeff

Your scangauge problem is easy to fix. Change your fuel type setting to Hybrid and the SG will stay on during your EOCing.

I have a 1999 Cavalier LS and use EOC often. I shift to neutral, kill the engine and immediately put car back into start position, then coast. This really helps when coasting to a light, sitting at the light with engine off, then starting car when light turns green. The Cavalier is an underachiever mpg-wise, but I have had success with this in city driving and on the highway.

Try installing a inexpensive bicycle computer with wheel magnetic sensor and cable connection (!) for easy EOC recording. That's the way to 'save' odometer miles for better resale value ...

Just a thought - your bad alt and batt may be the culprits. You will be using a fair bit of battery in an EOC in the "run" position. Your brake lights are on, your radio may be on, your dash lights, the ECU.... if you have an alternator that is dieing, it may be innefficient at recharging and really load up your engine.

I had to replace my battery a little while back because after a long EOC, then parking the car, i couldn't restart it! i had to bump-start about 6 times in 2 weeks and the girlfriend got sick of pushing so i had to get a new batt :)