|
Lincoln, NE | Herdboar,
From what I understand after researching this app, it's a linear relationship based on BTUs/gallon plotted against respective grade prices - so as to arrive at cost per BTU - which yields a cost-per-mile calculation.
They take it one step further and make calculations on a specific tank-fill-size. The tank fill size comes from custom settings when setting up a vehicle i.e. it's name and average mileage.
The way it looks to me their base math is:
Summer blend E-0 being 115,000 BTUs per gallon.
Winter blend E-0 being 112,500 BTUs per gallon.
E-98 (denatured) being 76,100 BTUs per gallon.
I've checked their math and it seems to be valid at each of E-% and prices I've tested.
E-40 would be 97,940 BTUs/gallon based on winter blend stock - as we have now.
So to be specific, if you blend to E-40 (as you mentioned) you probably have a 10% mileage penalty compared to E-10 - or a 13% penalty compared to E-0. The extra cost per fill would depend on price spreads between grades.
All the valid resources I find say MPG penalty is commensurate to the E-% in a blend. Pretty much universally agree on. Here's a link that pretty much validates that relationship on various vehicles:
http://www.fueleconomy.gov/feg/byfuel/FFV2013.shtml
Like I said, these people quantify the penalty in dollars and cents per fill size - based on your settings under Avg. Miles Per Gallon. I use it quite often. What the heck - it's free.
| |
|
Cost Per Mile Selection At Multi-grade Pumps
