Tyres Overview

Time to apply the basic knowledge of all tuning parts covered in both Tuning Shop and GT Auto sections. The very first upgrade that should be considered are the tyres. The tyres are the only thing that are in contact with the ground, so this is the best place in maximising performance within a Performance Point (PP) bracket.

When building for a specific PP, you have to greatly consider tyre type choice. Majority of your performance will come from the correct tyre choice. As a base rule I've noticed the best compounds for specific PP are:

• <500PP | Comfort Tyres

• <600PP | Sport Tyres

• >650PP | Racing Tyres

Finding the perfect ratio between soft, medium and hard tyres vs power, under a PP restriction is how you'll be able to unlock more performance potential. Harder compound tyres will give less grip compared to the soft compound, however you will be able to either increase power and torque or use more downforce. PP doesn't increase as much when using harder tyre compounds. In majority of builds the softest tyre compounds are preferred as having increased engine performance is pointless if you can't apply the performance benefit to the ground.

Do not be afraid to mix tyre compounds, using a slightly harder tyre compound on the front tyres may reduce PP. Allowing for you to spend the PP lost by, adding more power, decreasing weight, increasing downforce or moving the ballast to change the weight distribution. 

Secondly, there maybe vehicles that simply don't feel comfortable on the softest compound tyres. A few examples being the Abarth 595 SS '70 being undriveable on racing tyres. The grip given from the tyres is too much for the short vehicle track width allowing for the vehicle to roll over in all corners, at any speed. (track width is the distance from the left to the right tyre). Another example is the Ferrari Enzo '02, in terms of handling a slightly harder front tyre compound allows for a more controllable vehicle at high speeds.

The aim for Gran Turismo's physics is to allow for a highly accessible racing experience for the majority of people of all ages and abilities. Gran Turismo does this by having a very basic tyre model that has increased amounts of tyre grip. I believe GT7 does this by increasing the initial available tyre grip and the peak tyre grip. However because of peak grip has been increased, amount of slip angle for each tyre type / tyre compound is greatly reduced. This also means the reduction in grip after peak grip has been reached is a far steeper reduction in grip.

As the slip angle range has been reduced the experience will be identical to earlier builds of the game. Once peak grip has reached it's very hard to keep the car on the limit of grip without completely sliding out. This is effect has been slightly reduced since the most recent tyre physics update in February 2023. This can be proven by a loss in time with any loss in traction when trying to accelerate.

The stock setup is an obvious band aid to this. The current stock setup is unresponsive and soft, to allow for more controllable vehicle after peak grip has been reached.

With this in mind, you will find the most performance gain by maximising vehicle response before you reach peak grip. Unlike in real life, where you will find the most performance gain by maximising the controllability at the very peak grip. This is why many users in comparison state Gran Turismo 7 use "unrealistic" setup settings to be competitive. It all falls down to what the best way to use the tyre grip is.

Tyres are designed to operate at set temperature ranges to give optimal performance in relation to tyre wear. In all Gran Turismo games you have never been able to set tyre pressures. This leads me to believe there are set tyre pressures for the tyres, that increase and decrease linearly to the tyre temperature. On this basis with no other data on tyres other than tyre temperature, we can only rely on how a real world tyre handles when it is under or over the designed operating temperature.

When a tyre is under the operating temperature, the handling will feel like the tyres are under pressured, giving a slight disconnected feeling to the road when steering and a lack of overall grip when accelerating and braking. 

The following data has been collected from multiple different cars of all different drivetrains. A temperatures will vary as my  personal interpretation of what an under pressured tyre feels like on Gran Turismo 7 will be different.

The following data has been collected all combinations of tracks, tyres, weather settings and game states.