GTP Physics and Tire Updates - 2025 Season 2

The 2025 Season 2 build update includes a major overhaul of GTP physics and tires, for a much more realistic, challenging, and rewarding driving experience.

Tires now take longer to reach their optimal temperature, making the out lap a critical part of race strategy. Grip has been reduced, particularly at high speeds, meaning careful throttle control and precise steering are more important than ever. In fact, over a two-minute lap, the updated tires alone can be several seconds slower than before—but this is by design. Real-world endurance teams manage their out laps carefully, and now, you’ll need to do the same.

To make this update feel more authentic, we worked closely with real-world drivers with experience in both GTP and Hypercars. Their feedback played a crucial role in refining tire behavior across various conditions. Using our tire design tools, we iterated on the model over 100 times in pursuit of greater realism before finalizing the release spec—delivering a driving experience that more closely mirrors real-world performance on the track.

The former release missed the mark primarily in high-speed cornering performance, which resulted from too much grip. The adjusted model is true to life and can be a handful at times, especially when the tires are cold. iRacers should reacquaint themselves with their favorite GTP or the LMP2 in test sessions before jumping into a race with their iRacing peers. Practice leaving the pits safely and establishing warmth in the tires. What you experience will give you a greater appreciation for the skill involved in piloting these technologically cutting-edge and high-performance racecars in the real world.

Phase 2 of this update includes a complete overhaul of the hybrid system to bring it up to date with the design of the current real-world cars and appropriate rulesets, which remains on track for a Season 3 release.