Support/knowledge needed please

bb1boy · Post by **bb1boy** » Wed Jan 08, 2014 10:41 am

Hey guys,

Some dude on Facebook is telling me my JDM BB4 Prelude is meant to run on 91 octane fuel, whereas I'm sure the JDM models were tuned/timed to run on 99.. I can't find any evidence to back myself up though, am I right or wrong?

https://www.facebook.com/groups/2204764 ... ment_reply

Post by **Vtecmec** » Wed Jan 08, 2014 10:43 am

I think it's actually tuned for 100 RON?

bb1boy · Post by **bb1boy** » Wed Jan 08, 2014 10:47 am

Even better. Can you back that up with any evidence though??

Post by **Merlin** » Wed Jan 08, 2014 10:47 am

The US has a different octane rating classification.

Post by **Donald** » Wed Jan 08, 2014 10:48 am

^+1

Probably an American with diarrhoea grade fuel.

bb1boy · Post by **bb1boy** » Wed Jan 08, 2014 10:49 am

Merlin wrote:The US has a different octane rating classification.

Ah right, that's interesting.. not sure I can be bothered to argue with him now then.

Post by **Merlin** » Wed Jan 08, 2014 10:55 am

Apparently their 91/92 is about the same as our 97, "premium" fuel.

BMCC · Post by **BMCC** » Wed Jan 08, 2014 10:56 am

I believe the petrol in Japan is 91 (regular), 96 (super) or 100 (Super plus) RON. Not sure what the Prelude is tuned for in Japan but I'd think it is either 96 or 100 RON. The Yanks use PON rather than RON as there fuel rating.

bb1boy · Post by **bb1boy** » Wed Jan 08, 2014 10:58 am

^^that'll do me. cheers chaps.

Post by **Donald** » Wed Jan 08, 2014 10:58 am

Merlin wrote:Apparently their 91/92 is about the same as our 97, "premium" fuel.

BMCC wrote:I believe the petrol in Japan is 91, 96 or 100 RON. Not sure what the Prelude is tuned for in Japan but I'd think it is either 96 or 100 RON. The Yanks use MON rather than RON as there fuel rating.

Interesting, didn't know that!

According to Wiki:

There is another type of octane rating, called Motor Octane Number (MON), which is a better measure of how the fuel behaves when under load, as it is determined at 900 rpm engine speed, instead of the 600 rpm for RON. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON, however there is no direct link between RON and MON. Normally, fuel specifications require both a minimum RON and a minimum MON.

So apparently the rating they have is an average of RON and MON.