Understanding GT3 Tyre Temperatures in PMR: Core vs Surface

February 23, 2026

With update 1.6.0.1 for Project Motor Racing the GT3 class now has a new tyre model that works differently from before. One of its fundamental changes is tyre temperatures.

If you’ve been watching the tyre temperature indicator on your HUD while driving a GT3 car, and wondering why it seems to fluctuate more than before, here’s a rundown on what’s going on under the hood — and what you’re actually seeing in the cockpit.

On the Heads-Up Display (HUD) you will find a range of information. On the bottom right corner (by default) you will find the tyre temperature readout displays different temperature values.

These temperature values are what we’ll be focusing on in this blog post to give you a better understanding of how close-to-surface temperature, and core tyre temperature work and what’s the difference between the two.

Surface Temperature: What the Colour Indicator Shows

With update 1.6.0.1 changes were made to where the temperature is sampled from inside the tyre for the visual indicator on your HUD.

The colour graphic is now driven by a measurement point closer to the tyre surface. Because surface temperatures react very quickly to driving inputs, this means the colours can move around more than before. As you exit a corner and drive down a straight, for example, the tyre surface cools rapidly, which can cause the indicator to dip back toward blue — even though the tyre is still performing perfectly well.

In other words, the tyre model itself is behaving correctly. It’s just that the visual indicator is now more sensitive, and is reflecting moment-to-moment fluctuations in your surface temperatures.

We made this change to give a better representation of what the tyres are doing.

Core Temperature: What the Number Represents

The number you see for tyre temperature and the colour of the tyre graphic are not measuring the same thing:

• The number reflects the tyre’s core temperature — more stable and slower to change.
• The blue/green/red colour graphic reflects a temperature reading taken from a point closer to the surface contact patch, which changes much faster with braking, sliding, wheelspin, and cornering.

This means you can sometimes see the tyre graphic dip blue on a straight as the surface cools quickly, even though the tyre is still within a good operating window overall.

Both readings are valid. They’re simply showing different layers of tyre behaviour—surface activity versus the deeper, more stable core temperature.

Surface temperature helps you understand where you’re pushing too hard. A front left temperature rising suddenly in a left turn suggests you’re perhaps scrubbing them too much. Core temperatures reflect where your tyre’s range currently is.

The ideal temperature range is 70°C – 95°C (158°F – 203°F) with the current tyre model for GT3 class.

Use these temperatures in combination to get the most from your tyres.

Based on your feedback, we’ll be refining this further by adjusting how the temperature indicator behaves, along with widening the “green” optimal window so it better reflects real usable performance.

Clear, trustworthy feedback in the cockpit matters, and we’ll keep improving this as we refine the system.

Discuss and share your feedback in our community forum or in the official Discord server.