It looks as though the Canadian octanes are similar to
the U.S. octane. In my area, there is 87, 89, 91 & 93
though I've heard tale of some place selling 94 (I
believe that they go in odd numbered incriments of 2.)
A low compression engine (7.5:1) SHOULD be able to run
on 87 octane. If you get pre-detonation a.k.a.
pinking, pinging, knock, surface ignition, or marbles
in the engine; then move upto 89, or higher as
necessary.
In the U.S. we use a PON (Pump Octane Number) which is
the average of both MON (Motor Octane number) and RON
(Research Octane Number). PON = (MON+RON)/2
What is a MON and a RON?
MON and RON are both actually calculated by the ASTFM.
The MON being a value of resitance to pre-detonation
under extream conditions (high heat, high pressure,
high load). The RON being the value of the same
pre-detonation resistance under low-load, low speed,
real world driving conditions. The RON number tends to
be higher (obviously?).
In the U.K. they also use the ASTFM test, but only
refer to the RON number on pumps (from what I
understand).
If you look at the fuel pumps, the next time you go to
buy gas you will see that there is a sticker on each
pump stating that the octane rating is; pon, mon, ron.
What does U.K. Fuel octane equal in U.S. Octane? Well,
since the pumps in the U.S. don't tell us what the
MON/RON are (it only gives the solution to the
equation), all we can say for sure is that U.S.
gasoline (PON <-average of the high AND low number)
would be nearly equivelant to some higher octane
number in the U.K. (RON <- the high number alone).
There you have it...Everything you did and didn't want
to know about the proof of your (dino) juice.
-Terry
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