Use this ACC tyre pressure calculator to set your next cold pressures based on what happened in your last run. Enter your current cold and measured hot values, then get a per-wheel recommendation.
Current Cold Pressures
Measured Hot Pressures (after stable laps)
How to Use This ACC Tyre Pressure Calculator
In Assetto Corsa Competizione, tyre pressure is one of the fastest ways to gain confidence and consistency. This tool helps you adjust your next cold setup using what your tyres actually did on track.
- Set your unit (PSI or bar).
- Choose your target hot pressure.
- Enter current cold pressures and measured hot pressures for each corner.
- Optionally include expected ambient temperature change for your next stint.
- Apply the new cold numbers in setup before heading out again.
Why Pressure Matters So Much in ACC
Pressure directly affects the tyre contact patch, carcass behavior, and heat build-up. If pressures are too low, the tyre can feel lazy and overheated on the shoulders. Too high, and you may lose grip and traction over long runs. Getting pressure into the right window improves:
- Mid-corner stability and steering response
- Braking consistency
- Tyre life across race distance
- Predictability over fuel burn and changing track conditions
The Core Formula
The calculator uses a practical setup loop used by many ACC drivers:
This means if a tyre came in 0.4 psi under target, add 0.4 psi to that corner’s cold pressure next run. If next stint is warmer, reduce slightly; if cooler, add slightly.
Best Practice for Reliable Readings
1) Measure after stable laps
Don’t use out-lap or very early readings. Push 3-5 laps so temperatures stabilize, then log your hot pressures.
2) Record per-corner values
Left and right often differ due to track layout and camber load. Avoid using one average for all four tyres.
3) Re-check after setup changes
Big changes in toe, camber, ride height, aero balance, or driving style can alter heat generation. Revalidate pressures after major changes.
Typical ACC Pressure Targets
Target windows vary by update version, tyre model, class, and weather. For many dry GT sessions, drivers often tune around the high-26 psi range. Wet setups may differ significantly. The safest workflow is always:
- Pick a starting target.
- Run a controlled stint.
- Adjust using measured data (with this calculator).
Common Mistakes to Avoid
- Chasing one lap: pressure setup is for repeatability, not a single qualifying hero lap.
- Ignoring weather delta: even small ambient changes can move hot pressure.
- Using identical values everywhere: front/rear and left/right usually need independent tuning.
- Changing too many setup items at once: isolate pressure changes first when testing.
Quick Example
Suppose Front Left starts at 24.8 psi cold and comes in at 26.2 psi hot. If your target is 26.8 psi, you are 0.6 psi low. Set next cold to approximately 25.4 psi (before any weather compensation). Repeat this for each corner, and your setup converges in one or two runs.
Final Setup Checklist
- Use race fuel level for race pressure testing.
- Do at least a short run, not just one flyer.
- Log pressures after every stint.
- Adjust by corner and track temperature trend.
- Prioritize consistency over perfection.
Keep this ACC tyre pressure calculator in your setup routine and you’ll spend less time guessing, and more time driving stable, repeatable laps.