whats the difference between bridgestone s-03 and s-02 tires?

S-03 is the new, updated version of S-02, which is no longer produced...
 

still sold though - whatever is leftover in various warehouses.

S-03: Different tread pattern, longer tread life, better wet traction.

1

SO3 is good in the rain

Tread design is different, and compound "layout" changed.
 

Not sure if there were structural changes to the tire as well. Regarding the tread design, I think it was further optimized to keep tread blocks more stable under sheer forces. Regarding the compound layout...the S02's had a special layer of tread underneath. This compound was more resistant to aging (hardening from heat cycling), and it also had better grip in wet, at the expense of wear properties. (I may not be 100% correct here, but I'm close)

The S03's retain that same special tread compound, but they applied in in the shape of a "V" (if you're looking at contact patch as it makes contact with the pavement). This means that when the tires are new, very little or none of that special tread is exposed, however, as the tire ages, it exposes more of that special compound. Effectively, there is no longer an abrupt transition between the upper and lower compounds on the tire.

S03's were also formulated with a slightly longer lifespan (maybe 2-4K miles).

Thanks to all for the info, you may my mind up..
 

Bridgestone S-03s it is...

good to know, it hasnt rained in socal since i got them..

Try the Tire Rack for some info:
 

<ul><li><a href="http://www.tirerack.com/tires/bridgestone/bridston.htm">http://www.tirerack.com/tires/bridgestone/bridston.htm</a</li></ul>