Tell the EPA your MPG

The "Drivers Like You" Mileage over on the EPA's website for the Prius is down to 45.1 mpg, although its for only 45 vehicles. It would be really nice to see a larger sample size and hopefully better average. At least it should be closer to greenhybrid's 47.5mpg, based on their sample size of >1500.

You can go to the link below and setup an account to upload your data if you're interested:
https://www.fueleconomy.gov/mpg/MPG.do

BTW, I am in no way advocating tampering with the data. Just would like to see a more realistic number up there, and know we have a large group here with the real world data to make it happen.

Rob

 

Sorry, I guess I hadn't realized its separated out by year. Here's where each year stands:

2008: 45.1mpg, 45 vehicles
2007: 46.4mpg, 116 vehicles
2006: 47.7mpg, 112 vehicles
2005: 47.6mpg, 163 vehicles
2004: 47.1mpg, 63 vehicles

2003: 44.5mpg, 16 vehicles
2002: 44.6mpg, 22 vehicles
2001: 44.9mpg, 14 vehicles

Rob

 

Green Hybrid has 1566 vehicles in their database averaging 47.5 mpg. Looking at the data there it appears to provide a very good cross section of Prius drivers.

I'm not sure how they calculate their average, but I think their numbers are even low. I downloaded their complete dataset into excel a few weeks back, and I actually get 48.4mpg from their data. You get 47.6 if you do a simple average (sum(mpg)/n), but if you use the mpg and distance data to calculate actual gallons used and then sum up the gallons and miles and divide it out you get 48.4mpg. The formula I used is sum(miles)/sum(miles/mpg), which seems more accurate as it weights each mpg report based on how much data they have collected.

I do agree that people's averages do tend to improve over time. Its possible that is what we are seeing with the progression from 45 in 2008 to 46 in 2007, to ~47.5 in 2004-2006. If that were true though, you expect the '04 and '05 data to be better than greenhybrid's, to balance out the average rather than converging to the greenhybrid value.

Rob