Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 09, 2025 ...

Hmmmm....I wonder how much of that difference is "pump 'error' "?  I could swear that these pumps are "programmed" to yield less than the "pump reading" displays.

Well, I got the fuel from Pump 13 at the Flying J in Richfield, UT

Before you make that 1.085 a hard and fast correction factor, consider adding a half dozen fill-ups together and then calculating a correction factor.

On 8/29/2010 7:10 PM, Paul Smith wrote: 
Well, I refilled today in my 1999 U320. VMS predicted I used 140 gal. When I filled up it was 152 gal. No generator used. So this means I need to multiply VMS' estimate by 152/140 = 1.085, or just add 10% to VMS' prediction to be conservative.

 194-152 = 42 gal or 22% of a full tank. I doubt I'll play it this close again. Driving in the top half of the tank is a good feeling.

 1133 miles / 152 = 7.45 mpg. VMS had it as 8.1 mpg 8.1/7.45 = 1.087, effectively the same as the fuel difference alone.
___

best, paul
"Thriving not surviving" <(*¿*)>
Paul Schaye (at 2008 NYC Marathon)
See our blog at LazyDazers.com
 

Have you calibrated the VMS speed with a GPS?

Quote

  On 8/29/2010 7:10 PM, Paul Smith wrote: > Well, I refilled today in my 1999 U320. VMS predicted I used 140 gal. When I filled up it was 152 gal. No generator used. So this means I need to multiply VMS' estimate by 152/140 = 1.085, or just add 10% to VMS' prediction to be conservative.
 
  194-152 = 42 gal or 22% of a full tank. I doubt I'll play it this close again. Driving in the top half of the tank is a good feeling. >  1133 miles / 152 = 7.45 mpg. VMS had it as 8.1 mpg 8.1/7.45 = 1.087, effectively the same as the fuel difference alone.

Have you calibrated the VMS speed with a GPS?

My first thought is how would I have to drive my 36' 01 320 with 1 slide to get that poor mileage. Having driven it about 25K miles, flat land and mountains (eastern), If I got that kind of mileage I would be going over a few items, like air filter, tire pressure, toe in and dragging brakes trying to find a reason for the poor mileage

I find that identifying the actual fuel level in the tank is a lot harder than I thought, but with the size of the tank I know 5 or 10 gallons would not be hard to miss visually.  I have the fuel tank set at 190 gallons on my VMSpc just to have a little fudge factor and I'm thinking of lowering that amount to 185.

When you lean your coach to the curb (passenger) side to fuel, I hope you are filling from the street (drivers) side. I can easily visualize the process, trying to peek into the tank to see the fuel level.

I have adopted the procedure of filling with coach level and stopping at the first click on the nozzle. I know the penetration of the nozzle may not be consistent but this is as close as I know how to assume equal topping off as I can get, for calculating consumption.