Adjust Tacoma or midsize pickup tire pressure for temperature.

How does this Tacoma tire pressure calculator work?

Air in a tire loses pressure as it cools and gains it as it warms, so a tire set correctly on a warm afternoon reads low on a cold morning. The calculator corrects a cold pressure for the temperature change, so you can tell whether a Tacoma or any other midsize pickup's low-pressure light is the weather or a leak, and how much air to add. The load range table beside it shows why an LT truck tire is rated to a far higher pressure than you would drive on.

What do I enter?

• The pressure you set, in psi, measured cold (before driving).
• The outdoor temperature when you set it, in °F.
• The temperature now, in °F.

What does it show?

• Corrected cold pressure: the set pressure moved about 2% for every 10°F of change.
• The change versus what you set, in psi.
• A load range table (SL, XL, C, D, E) with ply rating and maximum inflation pressure.

What does 35 psi set at 70°F read at 30°F?

Set a tire to 35 psi (the calculator's starting value, close to a factory Tacoma placard; use the number on yours) on a 70°F afternoon. On a 30°F morning that is 40°F colder: 35 × (1 − 4 × 0.02) = 32.2 psi, a -2.8 psi change. Add that back, measured cold, to return to 35 psi.

The size of the tire does not change the math. A 265/70R17 and a 285/70R17 at the same pressure lose the same share, about 0.7 psi per 10°F at 35 psi, and more in psi terms on a tire run at higher pressure.

What does tire pressure read at each temperature?

Each column is a tire set cold at 70°F; each row is what it reads cold at another temperature, from the same formula as the calculator. Find your set pressure, read down to today's temperature, and the gap is the air to add or let out.

• Cold means before driving or after the truck has sat for a few hours. Driving heats the tires and raises pressure, so never let air out of a hot tire to hit a cold number.
• The 2% per 10°F rule is a close approximation for normal pressures and temperatures, not an exact gas-law calculation; a good gauge matters more than the second decimal.
• Set daily pressure from the door placard or, for LT tires, a load-inflation table for your axle weights. The table's columns are pressures, not recommendations; an E-range tire's 80 psi is its maximum, not a daily setting.

How is it different from a generic calculator?

• Truck load ranges side by side: the calculator puts the temperature correction next to SL (35 psi max) through E (80 psi max), so a Tacoma owner moving from factory passenger tires to LT tires sees both in one place.
• One visible rule: corrected = set psi × (1 + 0.02 × temperature change ÷ 10), so the result can be checked with a phone calculator.
• Cold-pressure framing: the tool corrects cold readings for the weather instead of guessing at hot pressure after a drive, which depends on speed, load, and sun.

Why does my truck's tire pressure light come on when it gets cold?

Because the air in the tires shrinks as it cools. A midsize pickup set to 35 psi at 70°F reads about 32.2 psi at 30°F, and the TPMS warning on many trucks trips once a tire falls far enough below its placard pressure. Add air cold to the placard figure; if one tire keeps dropping faster than the others in steady weather, look for a leak instead.

Related: 265/70R17 on a Tacoma · 285/70R17 on a Tacoma · Load index and speed rating.