<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by FrontRangeRVer:
The mileage gains are overstated. The power gains might not be....according to the dyno runs.
After my Ultrapower upgrade, new Taylor Extreme wires and regapped spark plugs, we gained no increase in MPG.
I agree with OEMTECH...it's really about the "drive ability" and not the mileage.
If people report they are getting 9 mpg, they are going downhill the whole time with a huge tail wind!

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I agree with the above. However, I might add that the speed you run at cruise has a lot to do with mileage. We help with the farm season here in central Illinois where the speed limit for motorhomes is 55 MPH. The landscape here is flat as a pancake and with no wind at 55 MPH I can get 9 MPG, sometimes a little bit over. I have the ultrapower upgrade. If I increase my speed to 60 MPH I can't get 9 MPG. At 65 MPH it closer to 8 MPG. Out west in the winter and pulling those hills I have seen it drop to 6 MPG.