In terms of doing an auto cross in wet conditions, I am thinking that just like with snow tires you need to use smaller width tires for the best full wet traction but I'm not positive if this is the case or not. Can somebody who has experience driving in the rain explain or confirm this?

 

Wide tires are more prone to aquaplane, but there is a vastly bigger difference to be had by actually using rain tires. They're a much softer compound that doesn't give a f*ck if the road is wet, plus the tread is usually designed to disperse more water.





Look at high end racing cars mang. They generally keep the same width of wheel/tire on their rain tires, but just change up the tire itself.

 

Void area is important. I don't think narrower tires would help.