I have had the VMSpc for a couple of years but only recently used it consistently on a cross country trip. I calculate fuel mileage. On this trip I compared the Fuel Minder (Fuel Used and Fuel Remaining) at each fill up. Consistently the fuel added is higher than the fuel minder reading. Example: Fuel Minder reported I had used 47 gallons but I pumped 57 gallons) This also makes the MPG appear higher on the VMSpc than my calculated. Is there a parameter I can play with to adjust so I can get the calculated readings and the VMSpc closer. Del Perry
The only time we encounter an error in mpg, such as you report, is when we run the gen set. The fuel used by the gen set is not measured by VMSpc or by the on-board monitoring system in our Winnebago. So when we fill we end up pumping in more than the system reports. Perhaps this is your situation.