Tires - BMW M4 GT4 User Manual

BMW M4 GT4 // TIRES & AERO

Tires

C OLD AIR PRES SU RE
Air pressure in the tire when the car is loaded into the world. Higher pressures will reduce rolling drag and heat buildup, but will
decrease grip. Lower pressures will increase rolling drag and heat buildup, but will increase grip. Higher speeds and loads require
higher pressures, while lower speeds and loads will see better performance from lower pressures. Cold pressures should be set
to track characteristics for optimum performance. Generally speaking, it is advisable to start at lower pressures and work your
way upwards as required.
HO T AIR PRES SU RE
Air pressure in the tire after the car has returned to the pits. The difference between cold and hot pressures can be used to
identify how the car is progressing through a run in terms of balance, with heavier-loaded tires seeing a larger difference between
cold and hot pressures. Ideally, tires that are worked in a similar way should build pressure at the same rate to prevent a change
in handling balance over the life of the tire, so cold pressures should be adjusted to ensure that similar tires are at similar
pressures once up to operating temperature. Hot pressures should be analyzed once the tires have stabilized after a period
of laps. As the number of laps per run will vary depending upon track length a good starting point is approximately 50%
of a full fuel run.
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BM W M4 G T4 // US ER M A N UA L