Trailer Tire Pressure Calculator: Find Your Optimal PSI
Calculate the ideal tire pressure for your trailer by entering your load and tire details below.
Understanding Trailer Tire Pressure
Proper trailer tire inflation is critical for safety, stability, and tire longevity. Unlike vehicle tires, trailer tires often carry heavy loads at sustained highway speeds, making correct pressure essential.
Trailer Tire Pressure Factors
| Factor | Impact | Consideration |
|---|---|---|
| Load Weight | Higher weight requires higher pressure | Calculate based on actual loaded weight |
| Tire Size | Larger tires can carry more load at same pressure | ST (Special Trailer) tires have different specs |
| Load Range | Higher ply ratings allow higher pressures | Never exceed max pressure on sidewall |
| Speed | Higher speeds generate more heat | May require pressure adjustment |
Trailer Tire Pressure Guidelines
| Tire Type | Typical Pressure Range | Max Pressure |
|---|---|---|
| ST175-215 (Small) | 35-50 PSI | 50-65 PSI |
| ST225-235 (Medium) | 50-65 PSI | 65-80 PSI |
| LT235+ (Large) | 65-80 PSI | 80-110 PSI |
| Commercial (11R22.5) | 80-110 PSI | 110-125 PSI |
Benefits of Proper Trailer Tire Pressure
Safety
- Reduced blowout risk
- Better stability at speed
- Improved braking performance
- More predictable handling
Tire Life
- Even tread wear
- Prevents sidewall damage
- Reduces heat buildup
- Maximizes mileage
Performance
- Proper load support
- Reduced rolling resistance
- Better fuel efficiency
- Smoother towing
Cost Savings
- Longer tire life
- Reduced maintenance
- Better fuel economy
- Fewer roadside failures
Pressure Recommendations by Trailer Type
| Trailer Type | Special Considerations | Typical Pressure |
|---|---|---|
| Utility | Often underinflated due to light loads | 35-50 PSI |
| Boat | Check after launching/retrieving | 50-65 PSI |
| RV/Camper | Heavy, sustained highway use | 65-80 PSI |
| Horse | Vibration concerns for animals | 50-65 PSI |
| Car Hauler | Front axle often carries more weight | 65-80 PSI |
Trailer Tire Maintenance
Pre-Trip Inspection Checklist
- Visual Inspection:
- Check for cracks, bulges, or damage
- Look for uneven wear patterns
- Inspect valve stems and caps
- Check for proper lug nut torque
- Pressure Check:
- Use heavy-duty gauge
- Check when tires are cold
- Compare to calculated ideal pressure
- Check spare tire pressure
Monthly Maintenance
- Detailed Inspection:
- Measure tread depth (minimum 4/32")
- Check for dry rot or weathering
- Inspect wheel bearings
- Verify proper alignment
- Documentation:
- Record all pressure readings
- Track tire rotation schedule
- Note any repairs or replacements
- Monitor tread wear patterns
Frequently Asked Questions
How often should I check my trailer tire pressure?
Trailer tires should be checked:
- Before every trip
- After significant temperature changes
- Monthly when in storage
- After loading/unloading heavy cargo
Why do trailer tires need higher pressure than vehicle tires?
Trailer tires require higher pressure because:
- They carry heavy concentrated loads
- They don't have suspension systems to absorb shocks
- They often sit stationary for long periods
- They experience different wear patterns than vehicle tires
How does temperature affect trailer tire pressure?
Temperature impacts trailer tires:
- Pressure drops ~1 PSI per 10°F temperature decrease
- Heat buildup from highway speeds increases pressure
- Check pressures in morning before temperature rises
- Adjust pressures seasonally
What are signs of improper trailer tire pressure?
Watch for these warning signs:
- Uneven or accelerated tread wear
- Excessive sidewall flexing
- Trailer sway or instability
- Increased tire temperature
- Visible tire deformation
Should I inflate trailer tires to the max PSI on the sidewall?
Sidewall max PSI guidelines:
- Max PSI is for maximum load capacity
- Often higher than needed for typical loads
- Use calculated pressure based on actual load
- Never exceed max PSI rating
How long do trailer tires typically last?
Trailer tire lifespan factors:
- 3-5 years regardless of tread wear
- UV exposure degrades rubber over time
- Proper inflation doubles tire life
- Storage conditions greatly affect longevity
Safety Considerations
Critical trailer tire safety practices:
- Never exceed maximum load or speed ratings
- Replace tires at first sign of dry rot or cracking
- Use proper jack stands when working on trailer
- Balance trailer tires for highway speeds
- Carry a properly inflated spare
- Check bearings and brakes regularly