Date: Thu, 27 Dec 2001 17:14:53 -0600
Reply-To: Joel Walker <jwalker17@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Joel Walker <jwalker17@EARTHLINK.NET>
Organization: not likely
Subject: Re: Subject: Fuel octane
Content-Type: text/plain; charset="iso-8859-1"
> All of this should be considered along with the driving environment.
It
> seems that an engine under higher and prolonged loads, such as a
> hill-climbing Westy, is probably going to benefit from the more
expensive
> gasoline.
in my experience, the octane makes no difference in MY buses ... not a
nickel's worth of difference. over the years, i've tried to even up
the tankfuls of the three octanes available in my area, just for
testing purposes. but since i'm cheap, the 87 octane usually has twice
as many tankfuls as the other two octanes. ;)
here's the results ...
1988 Vanagon
Thursday 27 Dec 2001 Page 1
Brand Oct Tanks Gals Cost Miles MPG $/g $/mi
Amoco R87 46 592.0 654.38 12,077.3 20.4 1.11 0.05
Bp R87 46 574.5 627.48 11,577.0 20.2 1.09 0.05
Chevron R87 46 617.6 689.15 12,214.0 19.8 1.12 0.06
Exxon R87 46 617.5 679.13 12,270.3 19.9 1.10 0.06
Shell R87 46 595.6 665.00 11,553.2 19.4 1.12 0.06
Unocal R87 43 580.1 618.57 11,418.2 19.7 1.07 0.05
Z-other R87 2 27.0 28.62 533.6 19.8 1.06 0.05
Z-start R87 1 15.7 14.10 0.0 0.0 0.90 14.10
Total 276 3,620.0 3,976.43 71,643.6 19.8 1.10 0.06
Amoco R89 23 300.2 343.26 5,774.0 19.2 1.14 0.06
Bp R89 23 313.6 367.39 6,231.3 19.9 1.17 0.06
Chevron R89 24 309.1 375.84 6,283.3 20.3 1.22 0.06
Exxon R89 23 297.8 345.06 5,655.4 19.0 1.16 0.06
Shell R89 23 301.6 353.11 5,997.0 19.9 1.17 0.06
Unocal R89 21 269.1 311.73 5,332.1 19.8 1.16 0.06
Total 137 1,791.4 2,096.39 35,273.1 19.7 1.17 0.06
Amoco P92 25 333.5 440.92 6,605.9 19.8 1.32 0.07
Bp P92 25 308.9 397.89 6,139.3 19.9 1.29 0.06
Chevron P92 25 316.2 418.87 6,377.1 20.2 1.32 0.07
Citgo P92 1 9.7 15.52 101.7 10.5 1.60 0.15
Exxon P92 25 315.5 410.99 6,427.0 20.4 1.30 0.06
Shell P92 25 325.5 413.68 6,561.0 20.2 1.27 0.06
Unocal P92 21 274.1 349.98 5,581.4 20.4 1.28 0.06
Z-other P92 1 3.5 4.28 55.6 15.9 1.22 0.08
Total 148 1,886.9 2,452.13 37,849.0 20.1 1.30 0.06
Totals 561 7,298.3 8,524.95 144,765.7
Averages per Tank 13.0 15.20 258.0 19.8 1.17 0.06
the z-start is the very first tank i put into the bus. i separated it
out like that to keep from lowering the stats for the brand/octane.
z-other is off-brands that i used over the years ... when i couldn't
find a station that i had a credit card for. :)
to my untrained statistical eye, there ain't a bit of difference
between them. now, it LOOKS like the premium is slightly higher. and
if you didn't know me, you'd think that, too ... but my tendency is to
fill up with premium only before a trip, so the mpg is a bit skewed
that way: the 91/92/93 (all condensed into 92 octane) gets a tad more
highway miles than, say, the 87 octane (which gets used mostly on
around-town trips).
and i don't think that 0.5 mpg would be a 'significant' result, in
this more-or-less unscientific test of mine. too many variables, i
think. :)
anyway, as far as i'm concerned, in MY buses, using the gasolines
available in MY area of the country, and with MY driving style, there
ain't enough difference to warrant use of the more expensive
gasolines.
so why do i do it? :) old habits die hard ... i kinda semi sorta
somewhat think or believe that maybe, just maybe, the higher octane
fuels 'clean' the injectors or something. oh, and i'm trying to be
fair in the test. yeah, that's it! ;)
unca joel
1988 GL
1987 GL Camper
1991 Carat
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