Zombie thread, 3 years old now since last post..............
Now thats its back, there is something that needs to be pointed out
Summer tires are best known for their grip and raw performance. This is THE type of tire to have for the best handling possible because the tire compound tends to be stickier and adheres to the ground more-so than other tires. As their name denotes, they are made for warmer temperatures. The rubber compound used heats up faster and becomes stickier and stays sticky. If you’ve ever heard of the term “keep the heat in the tires” or “warm up the tires”, this is just describing the process of warming the tires up so they are at their optimal temperature for providing the best grip. Summer tires also have some of the best wet condition performance. The tire treads on summer tires expel the water out from under the tire through the channels in the tread. A lot, but not all, of the tread patterns you see resemble a “V” which is one of the more efficient channel patterns to use to expel the water. From my personal experience, having a set of wheels with summer tires is the biggest "handling" upgrade you can do. Having the extra grip and feedback from a well-constructed summer tire trumps all of the other suspension mods in my book. Quick story: During my first co-op term in Charleston, I started auto-x. There was a guy at several of the events who had a first gen 3 running in the stock class only using R-comps(allowed). At the end of the day they had a PAX shoot-off where the top 10 PAX time drivers competed for $50. The Mazda guy won 2nd place compared to some of the cars that had full suspension mods and only street tires. Having the right set of tires can literally take seconds off of lap times compared to a similar or even identical car with different tires.
High performance summer tires are just that, tires intended for high performance use. The right tires can make your car handle better, but the wrong tires can make go wrong at the worst time. When choosing a tire, you should find one that provides a level of grip somewhat below the road holding potential that the mechanics of your suspension can provide. If you put a tire that is intended for track/autocross on a car with factory suspension, the grip provided by the tire can overwhelm that suspension when pushed hard. Once the suspension is at its limits, it is just the tires keeping the car on the road. A good bump or quick directional change can break the tires free and off you go into the weeds. Its better that your tire/suspension combination allows for some warning before you crash ( some understeer is really
good here). So, if anyone is considering extreme performance type summer tires, think about suspension upgrades that can actually make use of that level of grip first.
That being said, putting parts on a car does not make you a better driver. Good Autox times are quite often dependent on the driver, and much less on the car.