So I got my scangauge II installed and after only 2 days I must say I am totally impressed with this little gadget. My question concerns setting up the scangauge when you're running custom tunes. I was reading the manual about adjusting for bigger tires, but if you're running custom tunes you shouldn't have to do that step correct? My thinking is my truck already has a Troyer custom tune installed that knows I'm running 35" tires so since the the scangauge is plugged into the ODB connector then it should be reading the tune and know I'm running 35's. Correct?

Also it appears my speedo is 2 mph off. The scangauge will read 2 miles slower than my trucks speedo, but I don't think it's the scangauge. Reason for that is on the Navy base I work at they have those "Your speed is xx" digital readouts everywhere and everytime I pass one I notice it reads about 2-3 mph slower as well. I thought custom tuning was supposed to correct speedo issues?

Thanks

 

Bill Cohron of PHP has posted several times on this. For some brilliant reason, Ford has calibrated the speedo to read about 2 mph faster than actual. On mine, it's about +2 mph in the 70 mph range. At lower speeds, it's about +1 mph.

So, sounds like your programmer has done it's work properly and has told the PCM your correct tire size, gear ratio and so on.

We just have to live with Ford's idea of our speed. (Maybe it's to keep us from getting tickets).

- Jack

 

If your tune is calibrated for the tires then the Scan Gauge should be set to 0%.