How to Check Tire Pressure Correctly
Checking your tire pressure is one of the simplest yet most important maintenance tasks for your vehicle. Here's how to do it right.
Why Tire Pressure Matters
Proper tire pressure affects three critical areas:
- Safety: Under-inflated tires can lead to blowouts and reduced vehicle control
- Fuel Economy: Correct pressure can improve fuel efficiency by up to 3%
- Tire Longevity: Proper inflation extends tire life by 25% or more
What You'll Need
- ✓ Tire pressure gauge (digital or analog)
- ✓ Your vehicle's recommended pressure (found in owner's manual or door jamb)
- ✓ Air compressor (if adjustments needed)
- ✓ 5 minutes of your time
Step-by-Step Guide
Step 1: Check When Tires Are Cold
For the most accurate reading, check tire pressure when your tires are "cold" - meaning the vehicle has been parked for at least 3 hours or driven less than 1 mile. Driving heats up tires and increases pressure readings by 2-4 PSI.
Step 2: Find the Recommended Pressure
Locate your vehicle's recommended tire pressure in one of these places:
- • Driver's side door jamb sticker
- • Inside fuel door
- • Owner's manual
- • Our database at WhatsThePressure.com
Important: Use the vehicle manufacturer's recommended pressure, NOT the maximum pressure listed on the tire sidewall.
Step 3: Remove the Valve Cap
Unscrew the valve cap from the tire valve stem and set it aside somewhere you won't lose it.
Step 4: Press the Gauge Onto the Valve
Firmly press the tire pressure gauge onto the valve stem. You should hear a quick hiss of air as you connect. If you hear continuous hissing, the gauge isn't properly seated.
Digital gauges will display the reading immediately. Analog gauges will show a stick that pops out with the pressure measurement.
Step 5: Read the Pressure
Note the pressure reading in PSI (pounds per square inch) or BAR, depending on your gauge and location.
Step 6: Add or Release Air as Needed
If the pressure is too low:
- • Use an air compressor to add air
- • Check frequently as you inflate
- • Stop when you reach the recommended pressure
If the pressure is too high:
- • Press the valve stem center to release air
- • Release in short bursts and check frequently
- • Stop when you reach the recommended pressure
Step 7: Replace the Valve Cap
Always replace the valve cap. It keeps dirt and moisture out of the valve, preventing leaks.
Step 8: Repeat for All Tires
Check all four tires, including the spare if your vehicle has one. Front and rear tires may require different pressures.
How Often to Check
Regular Schedule
Check tire pressure at least once a month
Before Long Trips
Always check before road trips or highway driving
Seasonal Changes
Check when temperature changes more than 10°F
TPMS Warning
Check immediately if the TPMS light comes on
Common Mistakes to Avoid
❌ Checking Hot Tires
Wait 3+ hours after driving for accurate readings
❌ Using Tire Sidewall Pressure
The sidewall shows maximum pressure, not recommended pressure
❌ Forgetting the Spare
Check your spare tire - you'll need it when you need it
❌ Relying Only on TPMS
TPMS only warns when pressure is 25% low - check manually
Temperature Effects
Tire pressure changes about 1 PSI for every 10°F change in temperature. This means:
- • Winter: Tires lose pressure as temperatures drop
- • Summer: Tires gain pressure as temperatures rise
- • Daily: Pressure varies between morning and afternoon
Quick Reference
| Pressure Difference | Effect |
|---|---|
| 1-2 PSI low | Minimal impact - add air soon |
| 3-5 PSI low | Reduced fuel economy - add air now |
| 6+ PSI low | Safety risk - add air immediately |
| Any PSI high | Harsh ride, uneven wear - release air |