View Single Post
Old 06-04-2008, 10:02 PM   #198 (permalink)
EcoModding Lurker
Join Date: May 2008
Location: USA
Posts: 59
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by tom43571 View Post
I think fuel injector pulse information comes through the OBD. Isnt that how the scan gauge works?
I think OBD does not carry fuel injector info. Or it does, but only for some makers. I believe injector info is not part of the general OBD standard. OBD was designed about twenty years ago, and the primary impetus was smog control. That's what was on the mind of its designers, not helping drivers who were suddenly very motivated to deal with $4 gas.

Because it relies on OBD2, I think SG does not attempt to look at injector info. I think the Scangauge reports MPG via an estimation process, based on various indirect parameters, like airflow data. For certain cars under certain conditions, this can lead to problems with accuracy. Certain owners have noticed and reported accuracy problems. Aside from them, I have a feeling that a certain number of other owners are dealing with inaccurate data and simply don't realize it. I think certain kinds of errors probably have a tendency to balance out over the course of a fill. Therefore they will escape notice under the normal calibration procedure.

There are obviously many pros and cons when comparing SG and MPGuino. They are quite different. But the latter measures fuel flow in a more direct manner, and I think therefore has the potential to be more accurate, especially under certain conditions that seem to create problems for the SG. Maybe much more accurate. In this application, I think accuracy matters, and I think this is potentially a major advantage for the MPGuino.

But it's probably too soon to say for sure, and there will perhaps be similar issues with regard to errors that are not picked up by an ordinary calibration procedure.

I have enormous respect and admiration for the folks who are working on this. If the aggregate effort was expressed in dollars, it would be a big number.
  Reply With Quote