Tank 194 - 12 May 2009

This tank served me for 429.8 miles on 11.490 gallons of gas, making for
mileage of 37.41 per gallon. This had been my best mileage in a while.

It was also my 16th tank of the year. My 16th tank last year came on 13
May. So it feels proper to do a comparison, since the days are so
close.

As of the 16th tank, I had gone 6401.4 miles last year. This year I
have gone 6254.6 miles, about 150 fewer miles. Last year I had spent
$518.46 on gas at this point, but this year only $317.31, although from
the news you'd think we all were paying more today. How quickly we
forget that last year we paid over $3.50 per gallon at this time of the
year...

Tank 193 - The Bloodletting Continues

Well, the mighty Corolla passed 73,000 miles. Perhaps it is time to
replace spark plugs and clean the K&N air filter. So far in 2009, my
average fuel economy is 36.41, which is almost one mile per gallon less
than my 2008 average. That is almost a three percent decrease, and
unexpected.

So I will shortly go and procure a K&N air filter cleaning kit as well
as 4 new spark plugs. I have not done anything to these parts of the
car. I really haven't worried about any part of the engine or
drivetrain since the car was purchased new in 2005.

Maybe I ought to have the brakes looked at, although they passed
"inspection" just a few months ago.

Anyway, this last tank (the tank that caused me to think) went 394.3
miles on 10.862 gallons of gas, making for an average of 36.30 mpg.

What bugs me is that I have gotten much better numbers in the past.
This car isn't old enough to go downhill like this. If it's not the air
filter and/or spark plugs, I don't know what it may be.

I have been driving quite gently in recent weeks and still mileage is
comparatively crappy.

Cash Cab Tank "#1:" Suspect

So I refueled the Cash Cab after it went just 159.3 miles, because I
suspected that the dealer only filled the tank MOST of the way and not
ALL THE WAY. I sure hope I was right, because the trip computer claimed
19.5 miles per gallon and I calculated a mere 16.23 miles per gallon
after pumping it full with 9.816 gallons.

I regret not remembering where the fuel gauge needle was as we drove
away from the dealer. I think it was hovering near the F for Full, and
after refueling all the way it's just above the top of the F for Full.

This next tank ought to show how accurate the computer is. I am
beginning to feel that many of these mileage computers are just best
guesses, but tweaked to make you feel that you get better fuel economy
than you actually get.