Ah, I see the 'corrected' MPG handled by adjusting the indicated miles versus a fixed, course miles. But I was just thinking about the results and how using the EPA as a handicap impacted the results:
- 1st - 56.3 MPG, 1990 Jetta (EPA changed in 2008)
- 2nd - 101.1 MPG, 2009 NHW20 Prius
- 4th - 55.4 MPG, 2005 Scion xA (EPA changed in 2008)
- 10th - 86.8 MPG, 2010 ZVW30 Prius
Assuming the dealership wants to sell their inventory, where is their reward?
The results remind me of the "Green Human" Portland-to-Portland, 8,000 mile marathon that ended with the Prius being within 1 MPG of the 'winner', the Jetta ... a difference without a distinction. But it is a fundamental problem of any ranking based just upon the vehicle MPG relative to the EPA score ... especially when in 2008 the EPA 'moved the goal posts.'
Chris Hogan at PriusChat had suggested, price-performance, that eliminates the effect of the EPA handicap by bringing in the vehicle payload:
- vehicle volume * MPG => payload.mile / gallon
This would change the scores:
- 5,855 = (87+17)*56.3 :: 1990 Jetta
- 11,323 = (96+16)*101.1 :: 2009 Prius
- 5,429 = (86+12)*55.4 :: Scion xA
- 10,068 = (94+22)*86.8 :: 2010 Prius
This is scoring based upon the vehicle alone, the payload and mileage. It eliminates the EPA handicap that in 2008 gave our 52 MPG 2003 Prius an unearned, higher ranking than our 52 MPG 2010 Prius:
- 104% = 52/50 - 2010 Prius
- 126% = 52/41 (EPA 2008) - 2003 Prius
- 6,032 ft{3} miles / gallon - 2010 Prius
- 5,252 ft{3} miles / gallon - 2003 Prius
For the participants, a great day and nice drive. But for the sponsor, time, money and resources that might have brought in new sales prospect, what did they get? Why would a 2010 Prius owner ever enter again?
The only salvation is a 2010 Honda Insight didn't show up. The EPA 41 MPG would have made for an especially awkward moment.
Bob Wilson