black103 wrote:I read a couple of articles but still don't understand what these pulleys do....

In essence what they do is turn your accessories (water pump, p/s) slower which creates less drag on the engine and in turn allows yor car to accelerate more quickly.

You can also go on sites like Tire Rack's that give the spec's including revs per mile of most of the tires they carry...

01mmrgt wrote:yes but inbetween do you drive the car crank or what thanks

Yes, the car must be running to log data. DO NOT run the car when changing settings or downloading tunes or new settings.

Honestly, what type of performance gain were you looking for in your performance car by running anything less than 93 octane?
I agree. If you're spending the money for the tuner you'd better be able to support it with the fuel. Anyone who doesn't have access to 93 octane gas in their area can ...