Tank 124 - 26 July 2007

Filled up at the Fredericksburg Costco this morning with 10.943 gallons
of gas, at $2.639 per gallon.

I traveled 427.0 miles on this tank, which made for fuel economy of
39.02 mpg this tank, nicely above average for the year.

Reasons for such an increase in fuel economy:

1) average commute home time over the last week and a half has been
under 60 minutes. For my last tank, my trip home averaged about 74
minutes. More time idling in traffic = worse fuel economy.

2) Increased awareness of traffic ahead of me, and taking my foot off
the gas when I see brake lights ahead in the distance so my car
naturally coasts slower to match the speed of those cars without the
need for the brake. More coasting = better fuel economy.

This tank was my 25th tank of the year. I have spent $627.87 on gas
this year on my first 25 tanks. So I looked back at 2006, and the first
25 tanks in '06 cost me $627.46, practically the same!

I made this chart to show relationships among the first 25 tanks from
the last three years:

I posted it as a picture, but it looks bad. I'll work on improving the appearance of future charts...

Obviously, the big thing that jumps out is my gas expense for the first
25 tanks leaped from under $500 to over $600 over the course of one
year, an increase of over 20%.

There are other interesting relationships I will address in the future.
In the meantime, I continue to drive frugally in the Mighty Corolla.