values of ron and octane

[tberk@mindspring.com (T Berk)]

Andrew Basterfield wrote:
> 
> On Sat, 26 Apr 2003 16:43:10 -0400,
> "Josh20V" <mkii@nycap.rr.com> wrote:
> > Somebody care to explain the direct relation between ron and octane
> > levels? What ron does 87/93/etc octane in the US have?
> 
> I think RON is what you measure octane in.
> 
> In the UK normal pump fuel is 95 RON. My EW rocco will run on 92 RON
> according to the label, and has done nearly 100K, I'm thinking it would
> probably take a few more degrees ignition advance. Will this be OK? Any
> ballpark figures?
> 
> --Andrew
> 
> --
> http://cemetery.homeunix.org
> 
>   ----------------------------------------------------------------------
>    Part 1.2Type: application/pgp-signature



Keep in mind different parts of the world post differing values for
the same equivalent gas.   Here in the US we see that... 

>    Gasoline pumps typically post octane numbers as an average of
> two different values. Often you may see the octane rating quoted as (R+M)/2.
> One value is the research octane number (RON), which is determined with a
> test engine running at a low speed of 600 rpm. The other value is the motor
> octane number (MON), which is determined with a test engine running at a
> higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a
> MON of 90, then the posted octane number would be the average of the two
> values or 94.


So, lets take this as a series of three differing grades, low mid and
High test. If you have a low compression motor (8:1) then low grade is
OK, as long as you're not knocking, if you have a high compression
motor (10:1), most likely w/ a knock sensor, then High test is for
you. 

Advance the timing a bit and bump the octane value to avoid pinging,
(Knocking).

TBerk