Tyre Model

Tyres start at 100% health (fresh) and degrade each lap toward 0%. As tyres wear, lap time penalties increase.

Tyre Wear Per Lap

Each lap, tyres wear down by a small amount. The formula: lapWear = circuit.tire_wear_per_lap x racecraft_mod x pace_mod x technical_mod x weather_mod tyreHealth = max(0, tyreHealth - lapWear)

• <strong>Pace</strong> increases wear. A driver with high Pace pushes harder, costing tyre life. The increase can be up to 30%: pace_mod = 1 + min(0.3, effectivePace x 0.02)
• <strong>Racecraft</strong> reduces wear. A driver with high Racecraft is gentler on tyres. The reduction can be up to 60% for very skilled drivers: racecraft_mod = max(0.4, 1 - min(effectiveRacecraft / 25, 0.6))
• <strong>Technical</strong> slightly reduces wear. Smooth inputs and car control save a small amount of tyre life (up to 10%):

technical_mod = max(0.9, 1 - effectivetechnical x 0.007) Combined driving style modifier = racecraft_mod x pace_mod x technical_mod

• <strong>Weather</strong> also affects wear. Rain means less grip, which actually reduces how fast tyres wear:

• Dry: full wear (multiply by 1.0)
• Drying: 85% of normal wear (multiply by 0.85)
• Rain: 70% of normal wear (multiply by 0.7)

Running wets on a dry/drying track increases wear by 40% (multiply by 1.4) because the tyres overheat.

Degradation Curve

Fresh tyres are fastest. As they wear, lap times get slower. The penalty stays small for the first half of a tyre's life, then climbs sharply:

Tyre Wear	Health Left	Time Penalty per Lap	What This Means
0-10%	100-90%	0.0s	Fresh tyres, no penalty
10-25%	90-75%	0 to 0.4s	Near peak performance
25-40%	75-60%	0.4 to 1.2s	Small but noticeable drop
40-60%	60-40%	1.2 to 3.2s	Clear degradation, braking suffers
60-80%	40-20%	3.2 to 6.0s	Significantly slower
80-100%	20-0%	6.0 to 10.0s	Survival mode, extreme penalty

Running tyres to their last 20% costs several seconds per lap. Wet conditions cut these penalties in half because there's less grip available from the track anyway, so tyre condition matters less. So at 70% wear on a dry track you're losing about 4.5s/lap; in the rain that drops to ~2.25s.

Punctures

When tyre health reaches 0%, the tyre punctures. The car must pit immediately on the next lap. A puncture counts as an unscheduled pit stop.

Colour Coding

In the race readout, tyre health is displayed as:

• <strong>Green</strong> (>=60%) - Healthy
• <strong>Gold</strong> (40-59%) - Wearing
• <strong>Orange</strong> (20-39%) - Worn
• <strong>Red</strong> (<20%) - Critical

Strategy Implications

• Running tyres to 0% gives extreme penalties (up to ~10s/lap)
• The pit-skip mechanic lets you extend stints if tyres are healthy enough
• Wet weather reduces tyre wear, so you can run longer on the same set
• A high-Pace driver wears tyres faster than a high-Racecraft driver — balance your PRT distribution to suit the circuit
• See Pit Stops &amp; Strategy for how pit strategy interacts with tyre management