I got one back in November and love it. I have it on average mpg, instant mpg, intake temp and water temp. first pic is while coasting while in gear so that is why instant is high, when I have the clutch pushed in or in neutral while going 65 it reads about 135mpgs. This was about 15 miles after I had started driving. most I have seen at this spot is 24.0mpg average. I have to stop for an intersection and then it is mostly uphill but a very slight incline except for about a half mile of a steep grade that I almost have to downshift out of 5th.



then the second one is after I had stopped after having to stop at a gate to open it and close it manually, then drive 20mph in 2nd gear for 1/3 of a mile up the driveway and then also go up a short steep hill to park. this was after a 20 mile drive. most I have seen after stopping in my parking spot was 22.8mpg average.

 

I love mine too, I have a piece of angle aluminum velcroed there and the SGII has Velcro on back and bottom, have cords in the '07 FX4, '01 Merc GM, my wife's Subaru Forester, and my '95 Tbird. I use it in each.

I have been using mine since 2010 and from start to stop, if gassing at both , whether it's been 80 miles or 380 miles or more, as long as no resets .... that average MPG holds to within a tenth mpg of the math when done so I'm sure it's accurate. After all, it's measuring gallons per hour and miles per hour anyway, so it knows miles per gallon at any instant and average is just a function of time at each ..... easy for a computer.

Even then if I am starting and stopping between fill ups, I am still confidant the average mpg is true for that leg. Watching the instant mpg out the corner of the eye, keeping it as high as possible is like training your foot with old school vacuum gage, it'll teach your foot to save gas and $$$.

I like on long coasting how it goes to 999 mpg ..... fuel is cut off. Make a game of seeing how high you can get the avg mpg from town to the turn in to the driveway. I also can see how a little TC-W3 helps it, and how the 87 Perf Tune actually gives me better mileage than stock tune or the XS Mileage tune of my SC FP1865.

Love the X-gages, though I have them set in two differing formats depending on if the '95, the '01, or the '07. Some sensors are different and missing in earlier years. For the Subaru, I just use the basic gage functions.

 

I have used mine in my truck, my girlfriend's 06 4.7L ram and her mom's 4 banger 99 accord. The ram never hits higher than 57mpgs while coasting in drive. I used it on the accord because the temp gauge in the car reads low. Found out it runs at 160 degrees but when stopped and idling, it goes up to 220+. We drove to Denver and back to Colorado Springs and while moving I never saw it go above 165 degrees. Also in my truck at 6000ft it read 192hp which is pretty good for having 202hp stock + intake and custom vmp 87 performance tune. General rule of thumb is supposed to be a loss of 3% every 1000ft above sea level. I would be losing 18% or so and am not losing that much it seems.