[Nezil]

Originally Posted by widetyres

V power 99 is equivalent to 92.5 aki (the Mon is 86).

Great that you were able to get the MON value for V Power in the UK. Sadly that doesn’t mean that it’s the same in Sweden. In the US, it’s really hard to find the MON and RON values, but I read a document talking about how a US nationwide move to 95 RON was being proposed at one point, and the motion failed because several states, including California, wouldn’t be able to produce 95 RON at the same time as the other environmental restrictions already in place.

Apparently, the most important factor for forced induction and high compression engines, is sensitivity, which is equal to RON - MON. Your V Power quote was 13, which is really really good.

If we assume that CA fuel, which is struggling to achieve 95, so let’s say 94 RON, it would have a sensitivity of 6 (RON 94, MON 88) to achieve its pump rating of 91 AKI. This is the reason why CA and US fuel in general sucks, it’s not only the RON or MON but the sensitivity as well. The best fuel is one with a high RON and high sensitivity apparently.