Installed Scan Gauge II and ran the setup. It gives me a 7.5 to 8.0 MPG while towing. My actual MPG was 10.2. Any ideas on what to do? Also, when towing my T/T (8800 lbs) into a slight headwind, I can barely maintain 60 MPH with the pedal on the floor. Is this normal? See signature for vehicle specs.ThanksMOHOK

Your going to have to run the calibrate again...

Make sure you fill it up the same way both times at the same station at the same pump.

Also is your speed showing true to a GPS? Like my truck the stock speedometer is off by exactly 0.5 MPH so the odometer is typically off by 15 miles by the end of a tank. Double check you distance travel against a GPS to make sure its showing correctly.

The fillup calibration and the speed calibration ar important to get good accurate numbers...

Mile Per Gallon Calucation

Speed (Miles Per Hour) / Fuel Usage (Gallons Per Hour) = Miles Per Gallon

Gallons Per Hour Calculation

Speed (Miles Per Hour) / Miles Per Gallon = Fuel Usage (Gallons Per Hour)

Speed Calculation

Fuel Usage (Gallons Per Hour) x Miles Per Gallon = Speed (Miles Per Hour)

Now we will use the examples above to calculate MPG form fuel flow and speed.

65 MPH / 4.39 GPH = 14.80 MPG

i can never seem to get mine dead set....but this may be cuz i fill the tank up till there's fuel runnin over the overflow on top of the tank....but i think i got it somewhat close now....for best results, always fill up from the same level, at the same station, and even the same pump, maybe even the same time...haha

On my Toyota's it was always within .5mpg. Now on my Dodge its all over the place, but the 3rd gens don't do a very good job of transmitting load/fuel data thru the OBDII port. As far as the power issue, that seems a bit odd. Have you verified nothing is draging on the trailer brakes?

On my Toyota's it was always within .5mpg. Now on my Dodge its all over the place, but the 3rd gens don't do a very good job of transmitting load/fuel data thru the OBDII port.

You might check the RATE setting... You might turn it down to SLOW so it has time to catch up with the data on the CCD Bus... MENU>MORE>MORE>RATE Set it for SLOW for the Dodge and see if that helps...

You might check the RATE setting... You might turn it down to SLOW so it has time to catch up with the data on the CCD Bus... MENU>MORE>MORE>RATE Set it for SLOW for the Dodge and see if that helps...

According to SG its the OBDII on the 3rd gens, all of them do it. It shows less fuel being burned at 1500 rpms than at idle. At low load and low speed its not accurate. Part of the issue is LOD is FCA, not injectors... Its actually a little better with RATE at FAST, but RATE resets to NORM after each power off... so I don't mess with it. It would be really nice if they came out with some xGauge stuff for the Dodges.

According to SG its the OBDII on the 3rd gens, all of them do it. It shows less fuel being burned at 1500 rpms than at idle. At low load and low speed its not accurate. Part of the issue is LOD is FCA, not injectors... Its actually a little better with RATE at FAST, but RATE resets to NORM after each power off... so I don't mess with it. It would be really nice if they came out with some xGauge stuff for the Dodges.

Maybe we should bug them about that and request for Cummins XGauges to be produced...

specifically, a boost gauge feature.......and maybe hp gauge just for S&G's

For some reason when I unplug mine, it throws everything off again and it usually takes 2 additional tanks to get it to recalibrate 100%.

Maybe we should bug them about that and request for Cummins XGauges to be produced...

I have been bugging them for 2+ years about Dodge codes...

For some reason when I unplug mine, it throws everything off again and it usually takes 2 additional tanks to get it to recalibrate 100%.

Yeah boost would be real easy, equal to MAP-IAT pressure.

in my experiments with the ccd i have found that it is not a typical obd2 protocol. for scangauge to work with as many vehicle they will use the 5 main standards. here is more info on that: http://en.wikipedia.org/wiki/Obd2#OBD-II except for the CAN bus (limited to newer vehicles), obd2 is slow. that is why the data from my highway drives is choppy.http://forum.mopar1973man.com/showthread.php/1275-data-from-my-drive-on-the-highway the more stuff i monitor, the slower the refresh rate is. you can only send so much data in a (insert unit of measurement). it seamed my 99 connected using ISO 9141-2, with a 10.4k baud. i think our application of the CCD uses 60k-70k baud. also i think that the CCD is proprietary tech while OBD2 protocols are standards.