As an experiment, I ran with TW320 Vredstein Ultrac Vorti+ instead of the OEM TW280 Pirelli P Zero (Hyundai); both were the 275/35-21 stock sizes. My best lap time was 2.83 seconds slower than my best from the previous month on the OEM tires. I struggled for grip in intense braking and cornering. Speeds were universally slightly slower, except for the entry into T19, and I believe that was due to my new adoption of straddling the curb there. On the plus side, the Vredstein tire rubber compound seemed very durable.