||corners. Entire books have been written on this topic. I will stand by what I said before, in that, you should be focusing on finding the stickiest tire for your application. Here's why.
1. Tire loading (normal force on the tire) is the biggest determining factor of traction. You will more likely than not fail to increase the reaction force that the rear tires experience from the road.
2. A larger contact patch is always beneficial, but wider tires certainly do not delineate a larger contact patch. This is very much because of the fact that the total force applied to said tires remains constant, and the increase in width of the tire generally equates to a shorter contact patch in the car's longitudinal direction.
3. There are many factors that you can control, which will result in actual increases in traction, such as proper: tire inflation pressure, tire temperature, tread depth, camber angle etc. Most importantly, the coefficient of friction, i.e. stickier tire. I quote Dr. Randy Beikmann, "When a tire is rolling, but not sliding, the tread in the contact patch is primarily in static (stationary) contact with the road at any given instant, so its traction is limited by the static coefficient of friction."
In my opinion, don't over analyze it. Buy the highest performance tire that properly fits your wheels and make sure to check the temperature rating.