[s-cars] Re: Gas Prices

[MLP]

It's always seemed a bit counter intuitive to me, but I believe "octane"
is basically a measure of a fuels resistance to burning, i.e., the
higher the octane rating, the more difficult it is to ignite a
particular blend of gas.  As one fuel wag comments, often "... using
more octane than you need will not help power, in fact the slower burn
rate will actually cause you to lose some power...."  When discussing
octane, it can be important to know which octane rating system the
number under discussion comes out of, MON (for motor octane) or RON (for
research octane) or the happy blend of the two, (R+M)2 which is what's
most often displayed on commercial gas pumps.  I believe the other
popular name for the (R+M)/2 is AKI for Anti Knock Index.   For most
purposes, it seems that the MON system is the more "stringent" & for our
motors the most meaningful of the rating systems.  Low-speed and low
load knock characteristics are determined by the RON test method. The
MON method tests high-speed, high load, high temperature situations, in
practice these conditions exist during periods of high speed power
accelerations, hill climbing, or any period of high power output (sounds
like racing to me). Obviously the MON number will be lower, but it's the
one racers should concern themselves with. 

>From what I can tell, "octane" has very little direct relationship with
the amount of "power" (assuming "power" equates to British Thermal
Units) contained in any given measure of fuel.  Octane simply isn't a
measure of "power."  As an aside, while I don't ever see any change on
our local fuel pumps in Denver w/regard to its octane rating when we do
our annual fuel switch, FWIW Chevron offers the following BTU estimates:

 	conventional gas		115,000 BTUS
	Conv gas +ethanol 10%   111.100      off -3.4%
	Conv Gas +MTBE 15%      111,800      off -2.8%**

".. since adding oxygenating compounds to fuel increases octane,
refiners adjust the octane of the gasoline so that the octane of the
finished product will be the same ...."  
http://www.chevron.com/prodserv/fuels/bulletin/oxy-fuel/enrgycon.shtml
There can however be an indirect relation between octane and power since
some high octane gasoline components, particularly the aromatics, have
higher energy content.

Actually, in my experience we frequently pay quite a bit more per gallon
for gas in Denver than many other regions of the country regardless of
"octane" ~ this is more a function of (a) your regional markets
proximity to feed stock & refining capabilities; and (b) perhaps most
importantly STATE (I'll assume the Fed's take an equal bite) TAXES!!

Remember the 1960's 0.25$ a gallon gas?  What I always find exceedingly
amusing every time I hear our "short term memory cells" kick in with the
"Man, am I ever tired of being gouged by the seven sisters" conspiracy
theory of gas pricing, is the fact that gas costs at the pump have, in
relative terms, remained CONSTANT, despite our voracious rise in
consumption levels and apparent societal insatiable appetite for more
fuel for more than 40 years!

 http://tnr.com/easterbrook.mhtml?pid=1418 
 http://www.cato.org/dailys/09-06-03.html 

and, BTW most of these analysis frequently focus on the consumer's cost
at the pump.  I suspect that if you factored out that portion of what
one pays that goes to the gasoline company vs. that portion taken by the
government in fuel taxes, you might be surprised at where the lions
share of your cost per gallon is going.

Finally, only in my opinion, if gasoline costs were rising that fast, or
that unbearable, come on people, if all the soccer moms and save the
environment advocates etc., would consider switching from our collective
present propensity for Hummers and Tahoes and Ford Expeditions etc., the
Prius family of vehicles (I'm thinking that would have to equate to some
thing like an instant 3x to even 4x increase in our national gas
mileage), we would have a glut of 0.50$ a gallon gas on the market  :-) 

Mike "I get a wry, cynical kick out of Leno's JayWalking Episodes" P 
Who fought WWII?  What happened in Vietnam?  How many years ago was it
1950?  Why is gas so expensive?  Or you can pick from my brother in
law's warped sense of imponderable humor:

"In light of the Madrid bombing, France has raised their terror alert
level from "run" to "hide".  The only two higher levels in France are
"surrender" and collaboration"!  Not funny, right?

>-----Original Message-----
>From: s-car On Behalf Of James Shackelford
>
>John,
>
>It's all about altitude.  Here in Denver Premium is only 91
>octane.  Though we pay the same price as someone at sealevel 
>pays for their premium 93 octane.  I think it's a rip off, but 
>I do know that at altitude it changes. Though, since out 
>turbos compensate for altitude a bit I wonder if we could 
>still benefit from the 93 being sold here.
>
>James
>