iRacing has released details for their Season 4 build, delivering what may be one of their most comprehensive update in years. Following the substantial improvements introduced in Season 3, this latest release combines substantial new content, physics improvements, and technological advances with a complete user interface overhaul that sets the foundation for future development.
Substantial New Content Additions
Season 4 brings significant content across multiple racing disciplines. The Aston Martin Vantage EVO GT3 headlines the new car additions, developed through close collaboration with Aston Martin and professional drivers who race both the real car and in sim racing.
Open-wheel racing gains the Dallara IL-15 from the INDY NXT series, featuring a 2.0-liter turbocharged engine producing 450 horsepower. The carbon fiber monocoque chassis includes an integrated Halo device and push-to-pass system mirroring INDYCAR’s implementation.
GT4 racing expands with the Ford Mustang GT4, marking the first North American manufacturer in iRacing’s GT4 class. This addition accompanies a comprehensive GT4 class overhaul focused on improved correlation with the IMSA Michelin Pilot Challenge Series.
Existing BMW M4 GT3 owners receive the EVO upgrade free of charge, reflecting iRacing’s commitment to keeping content current with real-world developments.
Track Development Highlights
Autódromo Hermanos Rodríguez makes its iRacing debut with seven different configurations. Located 2,238 meters above sea level in Mexico City, the track’s thin air creates unique aerodynamic characteristics affecting both top speeds and cornering capabilities.
The venue’s distinctive feature includes sections cutting through a former baseball stadium, which will showcase iRacing’s upcoming audio reverb technology.
Season 4 completes the “NASCAR Refresh” project with art updates and rescans covering the final third of NASCAR’s schedule. This includes refreshes for Daytona International Speedway, Circuit of the Americas, Watkins Glen International, Chicago Street Course, and Texas Motor Speedway, plus rescans of World Wide Technology Raceway, Charlotte Motor Speedway’s Roval section, North Wilkesboro Speedway, and Sonoma Raceway.
All track updates are provided free to existing owners, representing significant added value for the community.
Physics and Class Updates
The GT4 class receives comprehensive physics improvements with updated engine power, weight adjustments, and redeveloped tire compounds for both dry and wet conditions. The changes improve real-world correlation while potentially reducing lap times by 0.5 to 1.0 seconds depending on track characteristics.
All GT4 cars benefit from updated traction control, ABS, and ESC systems where appropriate, along with improved dampers, brake systems, aerodynamic factors, and fuel system standardization matching IMSA regulations.
The GT3 class sees gear ratio adjustments across six of ten cars as part of ongoing Balance of Performance refinements bringing the simulation closer to real-world practice.
A fundamental hybrid system overhaul affects multiple car classes. GTP and Hypercar categories will seamlessly blend ICE and electric power to match maximum allowable output, while the Ferrari 499P receives electric-only drive above specified minimum speeds. Mercedes W12 and W13 cars gain fast regeneration modes, with larger LMP1 improvements planned for improved drivability.
Advanced Technology Features
VR users gain access to eye-tracking foveated rendering technology for supported headsets. This advancement prioritizes rendering quality exactly where users are looking, potentially improving performance and frame rates while maintaining visual fidelity across the entire field of vision.
Behind-the-scenes improvements include modern texture compression technology that replaces previous systems with more efficient and performant alternatives. While largely transparent to users, this change sets the foundation for future paint scheme expansion possibilities.
Season 4 brings significant content across multiple racing disciplines. The Aston Martin Vantage EVO GT3 headlines the new car additions, developed through close collaboration with Aston Martin and professional drivers who race both the real car and in sim racing.
Open-wheel racing gains the Dallara IL-15 from the INDY NXT series, featuring a 2.0-liter turbocharged engine producing 450 horsepower. The carbon fiber monocoque chassis includes an integrated Halo device and push-to-pass system mirroring INDYCAR’s implementation.
GT4 racing expands with the Ford Mustang GT4, marking the first North American manufacturer in iRacing’s GT4 class. This addition accompanies a comprehensive GT4 class overhaul focused on improved correlation with the IMSA Michelin Pilot Challenge Series.
Existing BMW M4 GT3 owners receive the EVO upgrade free of charge, reflecting iRacing’s commitment to keeping content current with real-world developments.
Global Accessibility Improvements
Season 4 introduces language localization beginning with European Spanish support for both iRacing and iRacing Web platforms. Additional languages including Latin Spanish, German, French, Italian, Portuguese, and Brazilian Portuguese will follow in December and March builds.
The localization project required substantial technical architecture changes and specialized translation processes to handle motorsport-specific terminology and contextual content accurately.
Future Development Outlook
Beyond Season 4’s immediate improvements, iRacing outlined several ongoing development projects. The new rendering engine continues advancing with improved shadow rendering, enhanced night lighting, integrated decal systems, and working DLSS prototype implementation.
Physics development focuses on foundational tire modeling improvements, force feedback enhancements, and multi-core physics processing for higher sampling rates and reduced latency.
Career Mode development leverages AI driver capabilities to offer structured racing outside official series, featuring racing ladder progression and save game functionality. Multiple development teams are prioritizing this feature though no release timeline has been announced.
Additional projects include Gen 4 drafting improvements, oval racing enhancements, dirt oval development, advanced AI capabilities through Microsoft collaboration, audio system upgrades, and animated pit stop additions.
The Bottom Line
iRacing’s Season 4 build represents a landmark release that modernizes core systems while delivering substantial immediate value. The new UI provides the foundation for future feature development, while extensive content additions and physics improvements enhance the current racing experience.
For existing iRacers, the free BMW M4 EVO upgrade and comprehensive track refreshes provide immediate value, while new content expands racing opportunities across multiple disciplines. The technological improvements, particularly VR enhancements and rendering optimizations, demonstrate iRacing’s commitment to staying current with evolving hardware capabilities.
The build’s combination of immediate improvements and long-term technological foundations positions iRacing well for continued development and feature expansion in coming seasons. For full details on all Season 4 changes, visit iRacing’s official development update.