JIM5.0

Oh yes, those are the reasons why I do not put much stock in the on-board mileage calculators.
I actually want to know the algorithms the MPG calculator uses. For some reason, I believe it is totally independent of the ECU and does not even factor in fuel consumption in its calculations. Sad, the ECU is an absolute wealth of knowledge for such calculations: You have the exact fuel consumption curve of the trips, down to the fractions of seconds.

Nuke

Since I keep a log of my fuel mileage at each fill-up, I reset the onboard each time. I'll average my mileage each month by hand and I let the onboard help me determine differences from tank to tank. Since 90% or more of each fill-up is usually the same trip day after day with the cruise control set at the same speed, the only variance is weather and fuel quality. I've found variances of up to 4 MPG from tank to tank with gas from the same station with the weather conditions being near-identical. My guess is the ethanol content. You'd never see it if you didn't reset the onboard at each fill-up.

AzPete

I guess in the GT, being to exact on the mpg's is not one of the selling points. As long as mine stays in the same ball park all the time, I know it is running right and not draining fuel on the ground.

Sorry I am not into knowing how the mpg calculations are derived at.....other than the effect my right foot has.....lol

Nuke

Correct. The onboards are not typically accurate as indicated by the years of info on the forum from those that do hand calculate (although my g/f's V6 is typically within 0.2-0.4 MPG all the time). Don't let the inaccuracy stop anyone from using it as a relative reading since variances can still be noticed and used to determine if something is amiss.

Unleashedbeast

[quote=Nuke;7363832]Give me at least a 45 minute head start. I gotta take my Aleve for these aching body parts and joints, and need time for the drug to set in before you hit me with that walker.



and NO, you can NOT dip into my stash of Viagra. It's all mine, and I only take it when I'm anticipating some action. Hmmm...never thought about taking it before every drive in the Stang. Is that why you are out of Viagra, been driving the stang too much?



^^^ Keep shifting that stick.

Nuke

With a chit eatin' grin on my face, I'll just let the rest of this alone...

...except to say that I did the very unusual and took the Stang to work today (sunshine and few people here) and saw triple digits on a section of long flat road with the RD quiet and nothing in visual range. NO viagra needed!

Unleashedbeast

ahhh....

I love WOT throttle in the Shelby, especially in 4th gear. Take it to red line, and call it a day.

Smile is so big after, people think I'm the Joker.