The US uses PON, which is the average of RON and MON. On average its about 4 below the same Europe rating and is considered to be more accurate a measure for todays cars. The European RON test is carried out at lower revs. So our 8=95 RON is about equivalent to 91-92 US PON.

Modern Engine Tuning by A.G.Bell gives a good explanation and is a very good book on REAL engine tuning.

Here is a look up table

RON (Europe) PON (US)
90 86.5
92 88.5
95 91
96 92
98 94
100 95.8
105 100
110 104.5

I'm stuck in Paris again with work this week so I might do a page on the different fuel measuring systems for my web site.

So it looks like your US gas is nearly the same as our petrol. Must be the US cars that suck then!!! wink

Mad Mole
Visit Mad Moles Mondeo Madness
2L Zetec, Cams, Stage 2 head, Valve work, Powerflow, Unichip, AEM Ram, K&N, Ecotek, 75mm Lower etc.
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