Hereís a couple of examples for high performance recreational vehicles -
Personal Water Craft made in USA -
Here you can see there is no specification for which type of octane number is referred to,
but knowing it was made in the USA primarily for that market, it will be AKI as that is required
on petrol pumps by law there.
||SUPER UNLEADED GAS
|Minimum Octane number
Off-road All Terrain Vehicle, made in Asia -
Here more info is provided about which octane is required. "(R + M) / 2" means Research plus
Motor, divided by two, which is exactly the way that AKI is calculated. However, the term AKI is
only commonly used in the USA, so the method of calculating is often listed for more international
||SUPER UNLEADED GAS
||91 ( R + M ) / 2 or higher
Light Aircraft engine, made in Europe -
||Leaded or Unleaded, or Avgas 100LL
||Minimum RON 95, 91 AKI
Hereís a different way of saying basically the same thing. Most gasolines
that meet 91 AKI will also be 95, or more RON. Both are listed here so that different markets
will be able to recognise the correct local grade. The low lead version of Avgas (100LL) is also
listed because where this engine is used itís likely to be available and meet the requirements.
In Australia or New Zealand all three of the above engines would need to use PULP or a higher
octane fuel, to meet the minimum requirements. Thatís because when you look behind the numbers
and determine the specís are written primarily for the North American market, then itís clear
that we need 91 AKI or 95 RON. However if you just noticed the "91" and thought to yourself
"Thatís the RON number for ULP, so ordinary unleaded is OK", then you could very soon be in for
expensive engine trouble.
How can you tell? Itís not easy because recreational vehicle fuel requirements are written for
the most likely country of destination. In the English language thatís usually North America,
but not always. If you canít tell just where the vehicleís fuel requirements are intended for,
then itís usually safe to assume itís North America and consider the octane number to be AKI.
That way you might end up spending a little more on fuel, but itís much better than the severe
engine damage from detonation that result when you use a low octane fuel in a high performance