New Larger Gas Tank

[SprintSki]

My 2016 Sprinter 4x4 gas tank is 25.5 gallons.

I will soon be replacing the old 25.5-gallon tank with a 48-gallon gas tank.

How should I proceed related to Fuelly?

Appreciate constructive comments,

Will

[Airstreamer67]

I don't know why the size of the gas tank would matter to Fuelly or to MPGs calculated or etc.

Just note the odometer readings at each fill-up and the gallons of fuel used and the MPGs are calculated for you.

[JockoT]

Originally Posted by Airstreamer67

I don't know why the size of the gas tank would matter to Fuelly or to MPGs calculated or etc.

It will for the first top-up of the new tank. Say you got 20 mpg with your 25-gallon tank. This would equate to 500 miles. If you run the 25-gallon tank empty at 500 miles, changed the tank then went and filled up it would take 48 gallons, which would work out at 10.4 mpg. After that everything would work ok but that one fill-up would slew the fill-ups for the life of the car.
I would fill the 48-gallon tank but subtract 23 gallons from the amount. This would keep the mpg correct if not the fuel added and the mpg is the important value.

[trollbait]

Originally Posted by JockoT

I would fill the 48-gallon tank but subtract 23 gallons from the amount. This would keep the mpg correct if not the fuel added and the mpg is the important value.

If tracking by the odometer, I'd do the same. There'll be a little error, but the amount will have little effect on long term numbers.


If the trip odometer is being used for Fuelly fills, just ignore the fill up that has the tank swap. No data entry, no messing up of long term stats. You could do a manual calculation if you must know what that one tank's fuel economy was.

IIRC, there is a missed fill selection for the odometer method that can be
used on the tank with the swap. It resets the odometer zero point for the calculation. That means going through a couple of tanks before getting results, but the results will be for the new tank.