Originally posted by Manya
wtf? here in australia our lowest buyable RON petrol is 92RON and over your side that's considered premium?
And here I was complaining that 98RON petrol is the only highest we can buy
The USA uses what is called "pump octane number" (PON), which was invented by Washington bureaucrats. It is the arithmetic average of the Research Octane Number (RON) and Motor Octane Number(MON). Before the bureaucrats got involved we used RON. MON is a more severe test - higher jacket and inlet temperature - and the difference is usually about 8-10 points and is called "sensitivity".
By adding/subtractng 4-5 points to/from USA PON to get RON/MON you end up with about the same RON as your commercially available gasolines.