The new tire model REALLY makes proper tire warming important. When you first leave the garage the tires are not up to their operating temperature and thus are quite slippery. Simply "burning rubber" isn't enough--it takes strong laps at racing speed to build up the internal tire temps. Some tires actually take a good 4 to 6 laps to bring them up to proper temperature. Keep this in mind as you are working on a setup--you have to turn a few laps to get a good feel for the changes you've made. This effect can be compounded when driving on a "green" track. The lack of rubber on the track surface can have a radical effect on how the cars feels. You'll find that as you progress through a weekend and the track continues to "rubber in" you may need to alter your setup to compensate. On a "green" track with cold tires you'll need to be EXTREMELY cautious until things start to warm up.