I'm in the Uk and have a 95 VTEC Prelude. It has a H22A2 motor and we have a new fuel available here from Shell called Optimax. It has an octane rating of MIN 98.6!! plus loads of other benefits (see http://www.shell.com)

Obviously this means my timing (OBD I) can be advanced to gain more power from the fuel.(as per what I have read and Shell's recommendation) My Honda mechanic wasn't convinced when I asked him to advance it, and said the optimum was the factory setting. Should I just ask him to advance it to the factory recommended limit? (marks above/below the red timing mark)

UK Fuel Spec for H22A2 is Min RON 95. The CR is 10:1

Any thoughts...

Tim

 

On my prelude I ran +2 degrees over stock, which was 17. Stock timing on the us obd1 motor was 15 degrees. I'd check for yours again though since you have the uk spec, even though we both shared the 10:1 compression ratio.

Jared