Model Forum / Radio Controlled / Water Models / March 2008

Hi all.  I'm a new member and fairly new to model boating but far from
new from mechanics and engines.

I'm a little confused about the comments made by Carlos(?) in the RC
boat tips page on Premium fuels.  If he's still around, i welcome his
input into these comments (and anyone elses for that matter).

He states that the reason that premium fuel is no better or not
reccomended is because the higher octane fuels burn slower.  I agree
that a slower burining fuel is no good in these engines but i fail to
see HOW these are slower burning.  According to my research and
experience octane levels do not effect combustion rates.  The octane
purely reduces the point at which detonation of the fuel occurs.
Technical information on Wikipedia (octane) and other sites confirm
this.

What they DO state is that although Octane level itself does not
increase power, generally the increased octane fuels also contain
larger components of fuels with more carbon-carbon bonds which have
more potential energy per unit than thier other carbon-hydrogen bond
friends commonly forming regular fuel.

This combined with 'real world' experiments by me and some friends
clearly show the benefits of premium fuels.

Now, i do admit, i'm in australia and Octane/RON levels in standard
fuel are 91 and Premiums go up to 105 here. It's also possible that
fuels here have more addatives and not just the extra octane rating so
these results could be skewed from what you might find in the US or
other countries.

I can't see how it could be said that these fuels are of little or no
advantage when the results are clearly visible to me.