Model tire falloff degradation curves, fuel tank stint limits, caution undercut timing, and total elapsed race time for multi-stage oval races.
On high-wear asphalt (e.g. Darlington, Phoenix, or Bristol), tires degrade rapidly. Taking fresh rubber saves 0.8–2.5 seconds per lap immediately, easily paying back the 40+ second pit lane penalty over a 60-lap stint.
The crossover point occurs when cumulative time lost to tire degradation exceeds the total time penalty of entering pit lane, stopping for four tires and 2 cans of fuel, and accelerating back to racing speed.
Cup Series fuel cells hold approximately 18.5 gallons. When track cautions fall near the edge of the fuel window, crew chiefs face the classic dilemma: pit for fuel now, or gamble on saving fuel under yellow to stretch to the finish.
At Phoenix and Nashville, Joey Logano and crew chief Paul Wolfe executed famous fuel-mileage victories by conserving fuel under green, running partial-throttle roll time through corners to eliminate a final splash-and-go pit stop.
In NASCAR, the undercut (pitting 2–4 laps earlier than the leader) provides brand new tires and clean air. If the leader stays out on old tires, the chaser gains up to 2 seconds per lap, cycling out ahead once all stops are completed.
Pitting under green carries extreme risk if a yellow flag drops before other competitors pit, trapping your car a lap down while the rest of the field pits under caution speed.