No, it is not recommended to put a standard passenger car tire on a trailer. While it might physically fit the wheel, car tires are engineered for different demands than trailer tires, and using one can compromise safety, handling, and longevity. The key difference lies in the construction: trailer tires have stiffer sidewalls to handle the significant lateral forces experienced during cornering, preventing sway. Car tires, with their softer sidewalls designed for ride comfort, are prone to overheating and failing under these conditions.
The load range is another critical factor. A trailer tire's load capacity is marked on its sidewall, indicating the maximum weight it can safely carry. A car tire of the same size often has a much lower load rating. Exceeding this rating is a major safety hazard. Furthermore, trailer tires are designed to run at higher inflation pressures (often 50-80 PSI) to support heavy loads, whereas car tires typically operate at lower pressures (30-35 PSI).
| Feature | Passenger Car Tire | Trailer Tire (ST) | Why It Matters |
|---|
| Sidewall Stiffness | Softer, for comfort | Extra stiff, reinforced | Preults trailer sway and instability |
| Load Capacity (Load Range) | Lower for vehicle weight | Higher, designed for cargo | Safety; prevents blowouts from overload |
| Tread Pattern | Varied, for grip & water dispersal | Often ribbed for stability | Better straight-line tracking and wear |
| Speed Rating | Higher (e.g., S: 112 mph) | Lower (e.g., L: 75 mph) | Matches typical trailer towing speeds |
| Heat Dissipation | Designed for vehicle dynamics | Built to handle constant load | Reduces risk of blowouts on long hauls |
For short, low-speed trips with a very light utility trailer, a car tire might work temporarily, but it's a significant risk. For any dedicated cargo, boat, or camper trailer, investing in proper Special Trailer (ST) tires is the only safe choice. They are a relatively small investment compared to the potential cost of an accident caused by a tire failure.
