I got my Edge Evo yesterday and got right to work. Updated the firmware, set the correct tire size (including .03 for the "squish") and reset the onboard mpg count. I set the Edge to monitor speed, ect, and instant and avg mpg.

When I got to work, the onboard computer read 13.3 avg mpg while the Edge read 16 avg mpg.

Which is more accurate?

I know I can fill up, reset the trip meter, do some driving, fill up again, and do the math, but as far as the comp readings go, which is typically more accurate?

BTW, 2004 Lariat Screw 4x4/5.4/Edge set at 2/Gotts/k&n drop in.

 

Neither, use good old fashion division.

 

average the two? division is really the only accurate way but the oboard computer will give you a good guestimate.

 

The Edge has a smaller number of trips to average in. The average will get closer and more accurate with time, but it is not as good as actual miles driven divided by the number of gallons used.

 

My truck is basically the same as yours, except it's a year newer. I've always found the "onboard" (dash) mpg figure to be more accurate than the average mpg value shown by the Gryphon/Edge. I'm certain the calculations are done differently for each.

Bill Cohron says the Edge/Gryphon values are averaged over 100,000 samples which equates to about 5-6 tankfuls of gas? I think the dash reading changes more quickly than the Edge/Gryphon reading, so I'm certain it uses a smaller sample size. However, I also find that neither one matches what I calculate using the old "miles driven / gallons added" calculation. So, I've really stopped using either display. Instead, I monitor the miles driven since last fillup and once in a while switch to "miles to empty" on the dash display.

- Jack

 

OK. I was hoping that the new Edge with updated firmware would give accurate MPG's (Especially since the reading was so pleasing to my eyes!)

I'll fill up tomorrow, reset the trip meter, drive for a few days, refill, do the math, and report back. I will also reset both Edge and onboard MPG readings and compare the computer results with the paper and pencil results.

 

Do you have to do any thing speacial to get the instant MPGs to work? On my new cts it read 0 the whole way home. is this function not supported by the 98s? Do I need to give it more time to figure out what is going on?

 

If it's reading 0, your truck's sensors are not providing the information needed to monitor this value. I'm sorry, and I DO think that Edge should be a bit more specific about what things CAN be monitored in the older trucks.

The newest trucks have a similar problem. There's no way to monitor the Oil Temperature. Ford decided that sensor was not needed, so you can't see it.

- Jack

 

Ok thanks so I geuss I wont have the feature t help me keep my foot of it. Granted I have gotten pretty good at watching my RPMs to help with that maybe I will use the Throttle Postion one and seee if that helps.

 

I suppose it could. One thing I'ved noticed is that the Inst MPG reading is pretty much the same whether or not you accelerate quickly from a stop or SLOOOWLY, but, you get to cruise speed where the Inst MPG reading goes up much sooner if you accelerate quickly *duh*. So, to spend the most time in an "economic state", I'd say accelerate pretty "briskly", not "drag race" style, but faster than most of your fellow drivers do it (traffic permitting of course).

You MIGHT get similar information by monitoring Engine Load, if you have that capability.

- Jack

 

Ok thanks, I do have the ablity for engin load.

 

inst. mpg worked just fine for me when i had my gryphon on my '98 4.6L. maybe try contacting PHP to see what they say about it.

 

You MAY have had a later build date on your truck. Some features get added mid-year.

You MAY also get a quicker response on the question of , "Can I monitor Inst MPG" if you call Edge Tech support. Bill Cohron is going to be out of town real soon for a bit and I suspect he's the only one who has a definitive answer on this question at PHP.

- Jack

 

my truck was built oct. of '97...about as early into the model year '98 as you can get.

 

OK, that shoots the "feature change" during the model year theory. I have no clue then why the CTS Inst MPG was reading 0 in your truck maddoughboy. There's nothing at all you have to do to make it work, other than select it as something to monitor.

- Jack