Re: [ihc] Octane selection

[Steven Stegmann <steve.stegmann@xxxxxxxxxxxxx>]

David,

When it comes to the exhaust system, octane won't have
any material effect on system life.  Don't even think
about that.

If it saves you money on fuel mileage do it.

BTW dieseling can be hard on an engine, if the premium
stops the dieseling, I would use it for that reason
alone.  If you have dieseling, you probably have some
hidden detonation also.  

Dieseling won't happen unless there is some "hot spot"
in the engine to ignite the last bit of fuel the carb
dumps in.  With a carb, unlike a fuel injection
system, you can't cut off the fuel, only the ignition.
 If there's still something hot in the engine, it can
diesel because it will get fuel as long as it is
turning.

Mild detonation is not good for an engine.  It's not
as bad as the "ping" that you hear but it ain't
helping anything.

Steve
--- David Bongo <dbongo@domain.elided> wrote:

> I heard something at work on Friday, and I wanted to
> throw it out here
> for you guys to comment on.
> 
> I got some coupons for "Shell V-Power Premium
> Gasoline" so, even
> though my effective price per gallon would be
> higher, I decided to try
> it.  The truck was dieseling just a bit, and I'd
> been told running a
> few tanks of higher octane gas could help clear it
> out, so I tried it.
>  The net effect was 2-fold: first, the dieseling
> stopped; second, my
> fuel economy on that tank went from about 7.5mpg to
> 8.5mpg.  Not a bad
> increase.  7.5 has struck me as slightly low, even
> for mail delivery,
> but within the bounds.  (I've been told that 10.9
> for my fuel injected
> 242cid Cherokee with headers and an O/D tranny was
> phenonomal.  So I
> figured 7.5 for a 258cid carburated  non-header
> equipped Scout II with
> no O/D wasn't terribly bad.)
> 
> Anyways, the station manager (a former Scout guy)
> told me that using
> the premium gas would help preserve the exhaust
> system, among other
> things.  Any truth to this?  Considering I'm
> (apparently) showing a
> 13% increase on economy, and with gas costing almost
> $2/gallon, it's
> probably worth it on that front alone.  Time will
> tell if that was
> simply a fluke reading or something legit.
> 
> On an off-topic note, can anybody give me any advice
> on home
> electricity generators?  We lost power for almost 17
> hours due to
> Hurricane Charley.  Fortunately, the refrigerated
> and frozen foods
> held up OK for the most part, but we're finally
> considering taking the
> plunge.  Propane or gasoline are options, and it's
> not like we need
> full power to the whole house.  Just refrigerators,
> mainly.  A few
> lights, too.  A/C, TVs, hot water heater, etc would
> be nice, but not
> really required.
> 
> Thanks in advance.
> 
> Dave