I recently switched from 700 x 28 Ultra Gatorskins to 700 x 32 Top Contacts. I normally ran the 28's at 110 PSIG in the rear and 100 on the front. I am running the Top Contacts at 85 PSIG on the rear and 80 on the front. I see no discernible difference in speed or effort but do see a difference (improvement with the Top Contacts) in comfort.