Patch notes:

GENERAL:

• CPU optimization on the game thread resulting in less CPU usage with AI.
• Added all cars' locations to shared memory.
• Added electronics channels to shared memory, in particular TC, TC Cut, ABS, fuel cons, engine map, exhaust temps, lights and wipers stages.
• Added initial TrackIR plugin implementation.
  • NOTE: a specific profile is required to be set up, please follow our forums for more information.

GAMEPLAY:

• Mid-session saving is re-enabled.
• Added ability to save multiple games and load then individually.
  • NOTE: Championship and Career can still only have a single saved instance.
• Now save games correctly handle car damage.
  • NOTE: it will only work with new saved games.
• Fixed a bug where restarting the engine was not possible in certain cameras.
• Fixed a bug with championship status when starting a new championship with another season in progress.
• Fixed wrong blue flag when only one car remains on the track.
• Reworked driver stint logic in Endurance game modes.
• Added driving time limit per driver in Endurance game modes.
• Added driver stint requirements per different Endurance modes as per real-life regualtions.
• Improved AI strategy in stint-based game modes.

AUDIO:

• Disabled possibility to trigger the Helicam audio during intro sequence.
• Stop&Go penalty engineer audio message.

CONTROLLERS:

• Mouse steering overhaul.
• Steering linearity added to controller settings.
• Race commands will not longer be intercepted for UI commands other than the directional pad (up, down, left and right).
• Fixed clutch limit bug when using maximum deadzone.

UI/HUD:

• Added Save Game window in the main menu to load saved games.
• Fixed chat window auto pop-in bug when receiving messages.
• Electronics and pitstop MFD page made more compact.
• HUD and car dash delta relinked to same source.
• Adjusted button alignment in the Replay menu.
• Fixed a bug where saving a setup with "/" in the file name would create a new folder.
• Fixed a bug where controller input was lost on the leaderboard page of the career and championship.
• Car previews now reliably load high-res textures in preview screens.
• Small car previews now reliably load on the Special Event pages.
• Added replay leaderboard and 'Toggle HUD' button in the replay HUD.
• Removed redundant "Driver" button on Player page.
• Updated UI background images and logos.
• Championship end-page logic review.
• Restyling of the championship and career pages.
• Added option to scale race HUD widgets.
  • NOTE: in this implementation it allows the player to resize the elements of the race HUD overall.
• Added "Continue" button for championship weather page.
• Added Save Replay and Save Highlights as configurable controls (the saving will have a 1-minute cooldown before allowing it again).
• Replay HUD now allows camera cycling during free camera.
• Disabled ideal line during replay.
• More reliable 'stop the engine' message during pitstops.
• Improved lapped information for realtime leaderboard when the cars are on the same lap.
• Improved filter for gap information in the realtime leaderboard.
• Added driver stint and remaining driving time information in the pit strategy page of the MFD.
• MFD now displays mandatory pit stop requirements in relevant game modes on the pit strategy page.
  • NOTE: it also displays whether the selected options meet the requirements and thus count towards a valid mandatory pit stop.
  • NOTE: maximum driving time is the key information to follow in endurance races.
• Added pit limiter popup display when entering the pit entry zone.

GRAPHICS:

• LOD adjustments on various models.
• Wheel rim material adjustments for various cars.
• Update to Black Falcon team liveries.
• Potential fix for the random open-close car door animations during gameplay.

PHYISCS:

• New 5 collision points tyre model. Tyres now "climb gradually" over kerbs, sausages, bumps both in lateral and longitudinal motion. Completely eliminates the "rail kerb" effect. Greatly improved behaviour over all kind of kerbs, improved precision, improved bumps absorption.
• Tyre model improvements to better handle high load peak situations and high rolling resistance peaks.
• Tyre model now simulates lowering of profile while the tyre flexes. Ride heights will be lower during turns.
• Tweaks to tyre model rolling resistance model. (Fixed and speed sensitive RR variations).
• New Traction Control operation. TC now simulates a two step operation, acting on the engine ignition timing (lowering power) and if that is not enough, cutting ignition all together as before.
  • This permits the TC to have a smoother operation at the start of a slide, permitting the driver to use the slide to turn the car without extreme vibrations or engine cut.
• New Traction Control logic. TC now takes into account the yaw acceleration, simulating gyroscope sensors as the real cars.
  • As a result, even if the slide or slip of the tyres is not enough, a sudden yaw acceleration (a fast rotation of the car) will activate the TC to save the car from spinning. It also works intelligently so that it can check if the yaw rotation is under control by the driver, allow him to use the power at will.
• Tweaks on the tyre pressure loss on rough surfaces (kerbs, off road etc).
• Car collider tweaks for various models.
• Fixed tyre core temps not properly saved and loaded.
• Fixed incorrect tyre wear when restarting race after loading a saved game.
• Tweaks to weather temperatures and sun phase.
• Tweaks to water dissipation rates.
• Fixed a setup bug with wet/dry setups on session changes.
• Fixed bugs related to setup naming.
• Fixed a bug with speed limiter status in neutral gear.

MULTIPLAYER & RATINGS:

• Automatic engines will start when the Pit Menu closes, so all engines should be on at the start of a formation lap.
• Rejoining a server while disqualified is now detected in all situations, locking down the car in the pitlane (instead of doing so on the straight after the first lap).
• "Speed up to 50kph" message will not trigger when starting in the pitlane.
• Pit menu selections now are more adaptive, also removing the "Setup" button as spectator.
• Slightly increased the ping limit for CP servers.
• Fixed long formation lap to not allow waiting in the first sector. Doing so will ignore the first lap.
• Added server health diagonistics, usable in the UI for further client updates and as admin command.
• Replaced "result" json outputs by a new structure containing more information like track, session data, all laps and all penalties.
• Json outputs now are also written when the session is advanced via /next command, or when the last player leaves and the server resets.
• Fixed the "rain" and "ambient" conditions setting having little to no influence on the dynamic weather.
• Reduced the rate of weather changes for high randomness settings.
• Activated the entryList setting "defaultGridPosition", allowing to resume a race any time (any Q session will overwrite the positions, but P->R would not).
• Added "dumpEntryList" flag, usable on non-public servers.
  • It will save all connected cars and drivers to a entrylist.json when a Q session is finished.
• Added admin command "/manual entrylist" to save an entrylist of the currently connected cars and drivers (on a non-public server).
• Fixed total race time having an offset in result jsons.
• Fixed playerIds not filled in the json results when defined by entry list.
• Fixed car category not being configurable in every scenario (using the entry list).
• Collisions during the race wait time won't affect the SA rating.
• Removed randomization from wrong tyre warnings.
• Updated server admin handbook version 3.

Source and more info