Tank 199 - 29 June 2009

This morning I refueled at the powerful Woodbridge Exxon near my office.
The strong pump squoze 11.468 quality gallons of Exxon gasoline into the
capacious tank of the Mighty Corolla, after I manfully drove it 439
miles.

This made for an impressive fuel economy for the tank of 38.28 miles per
gallon. I am pleased with this result because last Friday's commute
home was 97 minutes of slow, stop and go, mileage-sapping traffic.

Over the weekend, we had the grand opportunity to refuel the Cash Cab as
well. That tank received 17.324 gallons of Sheetz Quality gasoline in
Fredericksburg, and went 368.6 mostly around town miles, making for a
calculated fuel economy of 21.28 mpg. The trip calculator claimed 21.5
miles per gallon, which remains pretty close to actuality. Certainly
better than the Green Minivan that it replaced's estimates.

Additionally, the green minivan, granted with minimal data, provided
typical around town mileage of 15 to 17 mpg, and highway mileage that
pushed 23 or 24 mpg. The Cash Cab appears to be better both in town and
on the highway.

I learned over the weekend that the 2008 Sienna LE, with its
266-horsepower engine with variable valve timing-intelligent! Can whip
from zero to sixty miles per hour in 7.1 seconds, a full second faster
than the next fastest minivan, and as fast or faster than many cars on
the road today.

Not that I have ever timed it or tested this myself...

Tank 198 - 17 June 2009- Low Fuel Light Indicator Was Pretty Accurate!

Luckily, I needed gasoline yesterday right after I made up my cool new
chart that showed fuel economy vs. distance travelled when the low fuel
light came on.

For this tank, the low fuel light came on at 413.6 miles. According to
my collected data, this would indicate my fuel economy would be between
37.95 and 39.77 miles per gallon, with an average that should be 38.81
mpg.

So after going 440.2 miles, I put in 11.331 gallons of gas, and my fuel
economy for this tank worked out to be.... 38.85 mpg! That's really
close to the average fuel economy I have achieved when the low fuel
light comes on between 410 and 414 miles!!

Also, it looks like my last amazing mileage tank was not a fluke, but a
happy instance where the whole tank happened to be driven in an
unusually sane manner.

I have spent $426.49 on gas so far this year on 20 tanks of gas. Last
year at this time I had spent $650.77 on just 19 tanks of gas.

Overall, the mighty Corolla has gone more than 75,000 miles.

Chart- to go with below story- maybe this will be visible...

Low Fuel Light As Indicator of Fuel Economy

This morning I thought of something as this tank neared 400 miles so
far on my commute to work. I wondered if the miles driven prior to the
low fuel light turning on for good had any relation to overall fuel
economy.

So I spent a few minutes whipping up a couple of charts, and it appears
that there is a correlation between the time the low fuel light turns on
and the overall fuel economy for the tank.

File under "obvious," I guess, but it's kind of nice to know that when I
see that light turn on after I have gone 400 miles, it means I'm on
track for 38 mpg or better.

Tank 197 - I Don't Believe This Is Accurate...

So I refueled this morning at the Exxon station near my office
@$2.499/gallon. I went 450.9 miles on this tank, which is the third
farthest I have ever gone on a tank of gas in this car.

At this Exxon, I only squeezed in 11.053 gallons, making for a
calculated mileage of 40.79 miles per gallon, my fifth best mileage
result ever.

I strongly suspect that this gas pump is calibrated to shut off way, way
early. If my next tank ends up serving with 38 mpg or higher, I will
believe this tank's results with more trust.

Although I was driving with much greater attention to my acceleration
and braking, so it is possible I drove just that much more gently. On
the other hand, so far this year my mileage has been historically lower
than average.

Other notable facts from this tank:

Average tank distance is raised from 395 miles to over 398 miles per
tank.

Average fuel economy for 2009 raised from 36.53 to 36.75 mpg.

In 2007, I went an average of 8.54 days between tanks. In 2008, the
year I halfway carpooled, I averaged 10.08 days between tanks. So far
in 2009, that number is back to 8.53 days. Man, I wish I was carpooling
again. Kind of. I really am enjoying listening to my books on CD,
which I was unable to do while carpooling.

I have spent $398.17 on gas so far this year. Last year at this time I
had spent just $605.78, although gasoline was more expensive last year.
I have driven about 250 more miles in 2009 than the similar time period
in 2008.

In about a week and a half I will discover whether or not this 40.79
miles per gallon is just a sham.

Recent Tanks - Most Recently 31 May 2009

29 May 2009 - Tank 196 - 429.5 miles, 11.454 gallons, 37.5 miles per
gallon.

This is more like it but still not what I have grown to expect from the
Mighty Corolla. I believe some time in June I will eclipse my to-date
miles driven over 2008. Mostly because I no longer carpool. That's
sad.

On a happier note, on 31 May I refueled the Cash Cab and was surprised
at what I learned! The Cash Cab went 407.6 miles on 17.317 gallons.
The computer claimed 23.2 miles per gallon, but my calculation resulted
in 23.54 mpg. This is notable because the old green minivan was always
way optimistic with it's fuel economy guess, and here the Cash Cab is
truly pretty close, and actually a little under.

Also, computed fuel economy for the new minivan of 23.54 miles per
gallon is pretty great compared with what the old green minivan gave us.
But about half of those miles were highway miles. Still it appears the
new minivan will provide better fuel economy than the old one.