I believe ethanol contains less energy (BTUs or calories) per gallon than
gasoline, so you are correct in noting that adding ethanol to gasoline
will reduce mileage. I don't think "gasohol" is allowed to be sold in
this area, so I have no experience myself, and didn't consider it in my
reply.
Reynolds,John had this to say:
>Max,
>
>That's what I thought (regarding the higher octane in a newer car with a
>knock sensor); however, that doesn't apply when the octane is boosted with
>Ethanol - I actually get lower gas mileage on my 92 Ford CV when using the
>Ethanol.
>
>John Reynolds
>1979 MGB (in restoration) - will run on 87, too!
>
> -----Original Message-----
> From: Max Heim [mailto:mvheim@studiolimage.com]
> Sent: Wednesday, July 05, 2000 4:01 PM
> Cc: MG List
> Subject: Re: Octane and altitude ratios???
>
> Your Explorer may get better mileage with premium fuel since
>it has a
> knock sensor, which automatically advances the timing
>(within a limited
> range) until it encounters knock, then retards until the
>knock stops,
> several times a second, thus maximizing efficiency based on
>current fuel
> and conditions. Your B is unable to do this (obviously) so
>octane should
> not affect gas mileage (unless you adjust the timing to
>suit). The oil
> companies spend a lot of money trying to insinuate that your
>car will go
> faster, get better mileage, and be more reliable using their
>premium
> grade fuels, but for the most part that is baloney. You can
>advance the
> timing on your B to take advantage of high octane fuel to
>get some
> benefit, but the "proprietary" additives advertised, such as
>"Techroline"
> or "Techron", are mainly detergents intended for cleaning
>fuel injector
> systems on late model vehicles, and do nothing for
>carbureted engines.
>
> I have always suspected that the PO of my B's engine had
>planed the head
> (the donor car had headers and dual Weber DCOEs, which the
>wrecker sold
> separately), as it seems to require 92 octane fuel at the
>stock timing
> setting, to avoid knock and overrun. So YMMV. But in general
>there is no
> benefit to running higher octane than required to avoid
>knock.
>
> Andrew B. Lundgren had this to say:
>
> >That damage to the pocket book is what I am trying to
>avoid. I have a
> >Ford Explorer as well as an MGB that gets 15-16mpg... The
>owners manual
> >says 87 or higher, but I think that is calcualted for
>sea-level. When I
> >buy the highest available octain I get better gas
>mileage... This is just
> >one of lives mysteries I wanted to understand better.
> >
> >
> >On Wed, 5 Jul 2000 Gonaj@aol.com wrote:
> >
> >> Maybe I have misunderstood something in the past, but I
>am under the
> >> impression that your engine never needs a lower octant it
>simply nosen't
> need
> >
> >> the higher octane. In other words there is no loss or
>damage due to higher
> >> octane than necessary, other than to your wallet unlike
>the damage wich
> >> results from lower than necessary octane.
> >>
> >> If I am wrong here please explain.
> >>
> >> George
> >>
> >
> >
>
>
> --
>
> Max Heim
> '66 MGB GHN3L76149
> If you're near Mountain View, CA,
> it's the red one with the silver bootlid.
>
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.
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