2010 Mileage Report

Back in 2006 I took a statistics class at a local junior college as part of my transfer program to finally finish  my college degree. I needed to find a statistically interesting set of stats to study for my final class report. It took a while to decide but I remembered something weird. My wife learned a habit from her father: when you fill up with gas, always write down the information in a note pad for future reference. She records gas fill-ups, oil changes, brake and tire replacements, any service done on the car, etc. The information looks like this...

Car Mileage Recond

It is a simple spreadsheet in a spiral notebook. The data fields are date, mileage, fuel cost, gallons purchased, and dollars spent. You will also notice the notation of an air filter replacement and tranmission fluid flush/fill.

Using this data I came up with a range of interesting statistics:

1. Miles per gallon
2. Average miles driven per day/month/year
3. Dollars spent per day on fuel
4. Miles/time between oil changes

Since I always buy gas from the same place (when possible) the data also show the historical price per gallon in a fairly accurate way (regular unleaded). One of these days I'll post on my blog the results of the study I did regarding the relationship between gas prices, my driving habits, and my fuel buying habits.

Since putting all this data into Excel is a bit arduous I do it about once a year. This time around I found it had been 3 years since my last update to my ever-growing spreadsheet. I did buy the car new 14 years ago! (1998 Subaru Legacy L wagon)

What did I find out this year?

1. Average miles driven per day: declined 3 years running to 19.71. This is the lowest level since 2003 (18.84) and a significant drop over 2007 (27.33).
2. Total miles per year: same decline as #1, following the same trend. The high in 2007 was 9974 while the low in 2010 was 7195.
3. Gallons purchased followed the same pattern as miles driven but the changes in dollars spent was amplified by the volitility of fuel prices. 2008 was a lower mileage year than 2007 but a spike in gas prices in 2008 raised total fuel purchased to \$1416, a \$91 increase over 2007, and \$387 higher than 2010 (\$1029).

Bike mileage -

• 2007-08: 1475, avg. 737 per year (missed about 300 miles before I purchased my first odometer)
• 2009: 1727 = 784 (old odometer) + 943 (garmin.com, includes 450 miles for 2009 Cycle Oregon)
• 2010: 950 miles

Conclusions:

1. I'm a major nerd. Anyone who knows me will confirm that fact.
2. Buying my bike in 2007 dramatically reduced the miles I drive per year. 2003 was the year after our twins were born so we didn't go very far that year (not much other than commuting, plus vacation and 1 month infant care leave, all spent at home).
3. As my bike commute miles stack up the miles driven in my car continue to decline.
4. Gas prices are fairly volitale but still below the high of a couple years ago (\$4.35 on June 26, 2008)
5. My crash in August 2010 really put a dent in my annual biking mileage but not my car mileage.

The rest of this year should be even better than '09 as long as I stay injury free. I signed up for Cycle Oregon again this year, which should add another 500 miles, and I'm already above 200 miles for 2011 YTD. Maybe I can reach 2000 miles for the year?

Sorry Kris, I got nothin' on you...

Daily Mile Blog entry about Kris R, a guy I know from work.