With 9.5 compression you shure don't need a 93 octane fuel.
Even 91 is questionable.
And your Knocksensor is NOT going to have to retard timing.
Too bad you don't have access to a VAG tool ( VW diagnostic tool ), as you could actually watch your timing retard ( or NOT retard ).
As far as " The Kids " in the VW forums, hmmmmmmmm....we'll just leave this one as "No Comment ".

MTI
Are you into the spiked Coconut juice already ?

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2007 C 230 Sport.

Tis the season . . . and it's been raining all week.