View Single Post
Old 05-12-2008, 04:12 PM   #25 (permalink)
MetroMPG
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,532

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 62.14 mpg (US)
Thanks: 4,082
Thanked 6,978 Times in 3,613 Posts
Quote:
Originally Posted by monroe74 View Post
I'm also very intrigued by the possibility that WOT is optimal, and better than 70-80%, despite what I've heard about the penalties of open loop.
I'll just chime in an say that I also have doubts that the "rule" against going into open loop during P&G applies to all cars.

I've never spent much time watching loop status on the ScanGauge, except when I was initially curious to see how much time it took to switch over after a cold start. (Answer: in the depths of winter, no more than about 30 seconds).

But a couple of weeks ago, I called up that gauge while I was doing my usual P&G routine, and to my surprise, when accelerating I was in open loop most of the time! The transition point was much shallower than I had assumed.

I haven't tried to compare the difference between P&G with open vs. closed loop, but I will say that for my car at least, it doesn't appear to be a massive penalty. Consider the 104 mpg fill-up I saw last summer was using mostly open loop pulses (based on what I saw recently, using similar technique).

It definitely bears looking into.
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote