For years, one of the biggest frustrations in iRacing’s AI racing has been how computer-controlled opponents handled changing track and weather conditions. While human drivers naturally gained speed in cooler temperatures, AI cars often improved far more dramatically, leading to unrealistic pace differences. The result was that many players stuck to default afternoon weather when racing against AI — simply to keep things balanced.
That changes with the latest iRacing update. As part of the 2025 Season 4 Patch 2 release, iRacing has rolled out a major upgrade to AI tire temperature modeling. This improvement ensures AI tire behavior is much closer to the player’s, resulting in more natural and competitive racing across varied conditions.
What Changed with AI Tire Modeling
Previously, AI cars didn’t correctly account for how tires gained or lost performance as track and air temperatures shifted. Cooler conditions would see the AI gain disproportionate speed, creating frustration for players in practice, qualifying, or dynamic weather scenarios.
With this patch, the simulation now ensures that AI tire temperatures better mirror those of human drivers. That means lap times, grip, and handling characteristics scale much more realistically across cool, hot, damp, or changing conditions.
The update also ties into iRacing’s ongoing improvements to AI performance in rain. Players had noted that AI were lightning-fast on slicks in damp conditions, only to suddenly fall off pace in full wet. This patch begins addressing that imbalance too, with refinements to how AI handle drying and soaked tracks.
Cars Updated in Patch 2
This rollout covers a huge swath of the iRacing car roster. Any new car going forward will have the update, and many existing cars received the fix immediately in Season 4 Patch 2. Here’s the full list:
Updated Cars (2025 Season 4 Patch 2):
- Acura ARX-06 GTP
- Acura NSX GT3 EVO 22
- ARCA Chevrolet SS
- ARCA Ford Mustang
- ARCA Toyota Camry
- Aston Martin Vantage EVO GT3
- Aston Martin Vantage GT4
- Audi R18
- Audi R8 LMS EVO II GT3
- Audi RS 3 LMS TCR
- BMW M Hybrid V8
- BMW M2 CSR
- BMW M4 G82 GT4
- BMW M4 GT3
- Cadillac V-Series.R GTP
- Chevrolet Corvette Z06 GT3.R
- Dallara IL15
- Dallara iR-01
- Dallara IR18
- Dallara P217
- Ferrari 296 Challenge
- Ferrari 296 GT3
- Ferrari 499P
- FIA Formula 4
- Ford Mustang FR500S
- Ford Mustang GT3
- Ford Mustang GT4
- Formula Vee
- Global Mazda MX-5 Cup
- Honda Civic Type R
- Hyundai Elantra N TC
- Hyundai Veloster N TC
- Lamborghini Huracán GT3 EVO
- Late Model Stock
- Lotus 79
- McLaren 570S GT4
- McLaren 720S EVO GT3
- Mercedes-AMG GT3 2020
- Mercedes-AMG GT4
- Mini Stock
- NASCAR Camping World Chevrolet Silverado
- NASCAR Camping World Ford F150
- NASCAR Camping World Toyota Tundra TRD Pro
- NASCAR Cup Series Next Gen Chevrolet Camaro ZL1
- NASCAR Cup Series Next Gen Ford Mustang
- NASCAR Cup Series Next Gen Toyota Camry
- NASCAR Gen 4 Chevrolet Monte Carlo – 2003
- NASCAR Gen 4 Ford Taurus – 2003
- NASCAR Xfinity Chevrolet Camaro
- NASCAR Xfinity Ford Mustang
- NASCAR Xfinity Toyota Supra
- Porsche 718 Cayman GT4 Clubsport MR
- Porsche 911 GT3 Cup (992)
- Porsche 911 GT3 R (992)
- Porsche 919
- Porsche 963 GTP
- Ray FF1600
- Renault Clio R.S. V
- SCCA Spec Racer Ford
- Silver Crown
- Skip Barber Formula 2000
- Street Stock – Casino
- Street Stock – Eagle
- Street Stock – Panther
- Super Formula Lights
- Super Formula SF23 – Honda
- Super Formula SF23 – Toyota
- Supercars Chevrolet Camaro Gen 3
- Supercars Ford Mustang Gen 3
- Toyota GR86
- Williams-Toyota FW31
Community Reactions
The change has already sparked a wave of positivity across the iRacing forums.
- Endurance racers noted that this was one of the “biggest flaws” in AI, especially for dynamic IMSA-style championships. With GT3s already updated, players can finally run varied time and weather without broken pace gaps.
- Rain specialists welcomed fixes to AI behavior in damp vs. full wet conditions. One driver explained that AI had been five seconds faster in damp sessions on slicks, yet suddenly five to ten seconds slower once switching to wets. The new update helps smooth out these extremes.
- Stock car fans reported that Xfinity and ARCA cars feel far more natural in cooler conditions, making AI seasons much more enjoyable.
- Open-wheel racers were encouraged, though developers cautioned that some high-powered single-seaters (like the W13 and IR18) haven’t yet received the update — but will in the future.
Across the board, the community reaction has been enthusiastic, with many calling this the best AI patch note of the year.
What’s Next
While dozens of cars are now up to date, not every vehicle has the fix just yet. Legacy GT3s, certain open-wheel cars, and some older content remain on the old system. iRacing confirmed that all new cars will ship with the improved AI modeling, and existing cars will receive it during future updates.
This marks a major step forward for AI immersion in iRacing. Players can finally trust AI opponents to behave more like real competitors across a wide range of conditions, opening the door for more authentic offline championships and practice sessions.
