This is almost turning into the Predator page, but I have a question for the other owners. I purchased a Predator about two weeks ago, set it to the 65HP setting, not adjusting for tire size (BTW, I went from 245's to 265's). Towed a trailer of dirtbikes to Florida and averaged 22MPG on the DIC. Hand calculated to around 15MPG.
My buddy with me had a GPS showing my true speed was ~78MPH when the speedo showed 75MPH. Today I adjusted for the tires, I verified that the distances recorded on the odometer are now correct, but the DIC shows me getting 27MPG on the hwy at 70-75MPH and ~22MPG around town. As great as this sounds I know when I hand calculate it can't be that high. Can the DIC be brought back in line?

Nope. Not without removing the predator. The faster you go with the predator, the higher the DIC reads. I once had my cruise set about 90 or so and according to the DIC I was getting 32 mpg :p I wish.

Suppose tuning the tire size is a good excuse for getting the predator? According to the WHP when I had my cruise at 78 I was going 84. It was the best pullover I ever had. I saw him hit his brakes so I just stopped. He crossed the median and came up behind me, didn't even turn his light on since I stopped so quick. He walked up and asked what I had my cruise at, I told him 78 and he said "That's about what I thought when I walked up here and saw those big tires. I'm gonna write you a warning, you should go have the dealer set your truck to that tire size." I said thanks and he wrote me a warning, told me the formula for checking against the mileposts, and let me go. Wow. Never had one tell me my excuse before.
I did know it was off and that gm wouldn't set for 285s, I just wasn't that worried about it...

A reading of 26.8 got me a net of 18.8

A reading of 25.6 got me a net of 17.5

Wouldn't the high mpg on the DIC Average ( and maybe a few other numbers on the DIC ) tell the dealer that a programmer is on the truck ? You know, for warranty work. Just a thought. They would know better than anybody that the truck isn't averaging 27+mpg ! http://www.dieselplace.com/forum/images/smilies/hihi.gif

True, but I think those numbers can be reset anyway. I have a good dealer anyway. I bought the truck with my TST Powermax in it already. Nothing to hide with them.

I made a run to Nashville and back today running 75-80MPH. Hand calculated my average MPG was 17.5, DIC showed ~25. Now I just need to keep my foot out of it!):h

As I recall the DIC displays what the factory computer chip "sends" for fuel, anything additional that a performance chip ADDS isn't counted.

Stated another way, if it takes x horse power to push your truck/trailer up a particular grade at a certain speed then thats what it takes and the fuel to do that will be fairly predictable. If you have a performance chip the fuel that it commands is subtracted from the total, so the factory measurement (as displayed on the DIC) will be lower.

My local GMC dealer was selling them last summer. He actually believed the DIS readings and used those figures as a sales pitch. A friend called me and asked if that could be true. I told him no before I even checked on the forum. He sold his Edge with Attitude for $600 and bought one anyway. I asked him to run a few tanks, do the math and let me know. Haven't heard from him since. Go figure! I have another friend that bought an O LB7 with a dealer installed Hypertec. His first trip he claimed a 22 mpg average here in the Rockies. I suspect his DIS is screwed up also. Later! Frank