Somewhat OT but maybe useful to some: a way to get mid-grade gas cheaper
Larry Harvilla
mid-grade gas -- not regular or premium, but only mid-grade -- for less
than the pump price. It requires a wee bit of extra work, yes, but the
general theory relies on three simple facts.
Two of the facts are easily verifiable by any member of the motoring
public, and the third is based on a bit of my insider knowledge as
somebody who hauls fuel. They are as follows:
(1) In most places, the three grades of gas are 87 regular, 89
mid-grade, and 92 or 93 premium. Some parts of the West, especially at
higher elevation, may have 85/87/91, but as a general rule, mid-grade is
two points higher than regular and premium is usually 4 points higher
than mid-grade.
(2) Most gas stations have an even pricing gap from one grade to the
next, often 10-12 cents. For example, a station might have regular at
$2.599, mid-grade at $2.699, and premium at $2.799.
(3) Here's my insider bit. A fair number of gas stations don't even have
a separate underground storage tank for mid-grade; they produce
mid-grade by mixing the required fractions of regular and premium in the
underground piping between the storage tanks and the pump. For those
stations that do have a separate mid-grade tank, mid-grade is most often
obtained from the fuel terminal in the same way -- mixing regular and
premium base gasolines.
Let's assume a six-point octane difference between regular and premium
(e.g., 87 vs. 93) and an even ten-cent price differential from one grade
to the next. With a wee bit of leg-work, you could achieve the same
effect of a mid-grade fill-up for only 6.6c per gallon more than the
price of regular, saving 3.3c per gallon off the mid-grade pump price.
It's quite simple. Get some idea of how many gallons you need (e.g.,
let's say you have a 25-gallon tank currently just above 1/4; that's 18
gallons). In one transaction, pump two-thirds of that amount of regular
into your car, then in a separate transaction, the remaining one-third
in premium.
The math:
12 gals regular @ 2.599 = $31.19
6 gals premium @ 2.799 = $16.79
18 gals total = $47.98
18 gals mid @ 2.699 = $48.58
It is up to the reader to decide if the $0.60 savings in this example
fill-up is worth it.
One's savings would be increased by a higher differential between
grades, and reduced if the station in question sells 92 octane as
premium instead of 93 (as the required mixing fraction changes to 60%
regular and 40% premium with 92-octane premium, instead of 2/3 regular
and 1/3 premium with 93).
I know this may not be useful to too many folks, as most cars these days
only call for 87, and almost all of those that need higher octane call
for 92/93, but it could be helpful, so here ya go.
--
Larry Harvilla
e-mail: larry AT phatpage DOT org
http://www.phatpage.org/
http://www.flickr.com/photos/larrysphatpage