Pick your vehicle, add people and gear, and get a cold pressure for each axle.
Both tires on each axle, from a scale weigh-in with people and cargo aboard.
The last letter after the load index, like the "V" in 98V.
Terrain sets the target. The result never goes below what your load needs.
Estimate only. Load follows the Tire and Rim Association curve, load proportional to pressure to the 0.585 power, rated at 36 psi for standard and 42 psi for XL (35 and 41 for P-metric), and at the load range pressure for LT tires. Capacity stops rising at that reference pressure; the sidewall max is only a ceiling. Needed pressure is the reference times (load per tire ÷ max load) to the 1.71 power. Speed adds up to 1.5 psi per 10 km/h above 160 km/h (190 for W and Y), up to 7.5 psi, then cuts load 5% per 10 km/h, following ETRTO practice. That increase is defined at full rated load, so each axle gets it in proportion to how loaded its tires are (needed pressure ÷ reference pressure), the way BMW's high-speed tables give each axle its own increase. Off road, above 40 km/h the pressure rises to the road minimum. Vehicle data comes from manufacturer spec sheets and published placard lists (TirePressure.com and Firestone Complete Auto Care fitment charts). Front weight shares are estimates unless marked measured. For the trucks, SUVs and newer additions, curb weights are typical values for the trim and are marked typical. Load indexes and speed ratings come from the listed tire sizes; for the 2026 additions they are typical. Your sidewall and door placard win. Where a placard isn't published, enter yours. Check cold, never exceed the sidewall max, and confirm with your owner's manual.