In short, yes, you can usually put bigger tires on your trailer, but it’s not as simple as just choosing a larger size. Careful consideration must be given to several factors to ensure safety, performance, and avoid damaging your trailer or tow vehicle.
Understanding the Implications of Upsizing Trailer Tires
Simply put, increasing your trailer tire size impacts several critical aspects of its functionality. While it might seem like a straightforward swap, neglecting the underlying considerations can lead to disastrous results. You need to evaluate load capacity, clearance, axle rating, and much more.
The Allure of Larger Trailer Tires
Many trailer owners consider upsizing tires for a variety of reasons:
- Improved Ground Clearance: Larger tires increase the distance between the trailer and the ground, reducing the risk of scraping on uneven terrain. This is particularly beneficial for off-road trailers or those used on unimproved roads.
- Aesthetically Pleasing Look: Let’s be honest, bigger tires often look better. A more aggressive stance can enhance the overall appearance of your trailer.
- Potentially Higher Load Capacity: Some larger tires offer a higher load-carrying capacity than smaller ones. This can be tempting if you frequently haul heavy loads, though it’s crucial to stay within the trailer’s overall GVWR.
- Potentially Improved Ride Quality: Larger tires, especially those with a higher sidewall aspect ratio, could absorb more road imperfections, leading to a smoother ride, although this is highly dependent on tire type and pressure.
The Potential Pitfalls of Ignoring the Details
However, failing to properly assess the suitability of larger tires for your trailer can lead to serious problems:
- Safety Concerns: Incorrectly sized tires can compromise handling, braking, and stability, increasing the risk of accidents.
- Damage to the Trailer: Tires that are too large can rub against the trailer’s frame, fenders, or other components, causing damage.
- Reduced Fuel Efficiency: Larger tires can increase rolling resistance, potentially reducing your tow vehicle’s fuel economy.
- Incorrect Speedometer Readings: If your tow vehicle relies on the trailer’s wheel speed for stability control or other systems, changing tire size can throw off these readings.
- Voiding Warranty: In some cases, using non-standard tire sizes can void your trailer’s warranty.
Key Considerations Before Upsizing Trailer Tires
Before investing in larger tires, meticulously evaluate these factors:
- Load Capacity: The load capacity of the new tires must meet or exceed the gross axle weight rating (GAWR) of your trailer axle. Never use tires with a lower load capacity, even if they are larger. This is non-negotiable for safety.
- Clearance: Ensure there’s adequate clearance between the tires and the trailer’s frame, fenders, and other components. Check the inside, outside, and top of the tire during suspension compression. Turn the wheels (if applicable) through their full range of motion to check for rubbing.
- Axle Rating: The axle rating represents the maximum weight the axle can safely carry. Upgrading tires doesn’t increase the axle’s capacity. Overloading the axle is dangerous and can lead to failure.
- Rim Size and Offset: The new tires must be compatible with your trailer’s rim size and offset. Using the wrong rims can cause handling problems and potentially damage the axle or bearings.
- Bolt Pattern: Verify that the new wheels (if necessary) have the correct bolt pattern to match your trailer’s hubs. Using the wrong bolt pattern can prevent the wheels from mounting properly and securely.
- Overall Diameter: Consider the overall diameter increase. A significantly larger diameter can affect the trailer’s ride height and potentially impact towing stability.
- Tire Pressure: Maintain the correct tire pressure as specified by the tire manufacturer. Over- or under-inflated tires can reduce handling, increase wear, and pose a safety hazard. This information is usually found on the tire sidewall.
- Trailer’s GVWR: Never exceed the trailer’s Gross Vehicle Weight Rating (GVWR). The GVWR is the maximum permissible weight of the trailer, including its cargo. Even with larger, higher-capacity tires, you’re still limited by the GVWR.
Seeking Professional Advice
If you’re unsure about any aspect of upsizing trailer tires, consult with a qualified tire professional or trailer mechanic. They can assess your specific trailer and needs, and recommend appropriate tire sizes and wheel options. It is always better to be safe than sorry.
Frequently Asked Questions (FAQs)
Here are some common questions about upsizing trailer tires:
1. How do I find my trailer’s GVWR and GAWR?
The GVWR and GAWR are typically found on a sticker or plate located on the trailer’s frame, often near the hitch. You should also find it in the trailer’s documentation.
2. What does ‘load range’ mean on a trailer tire?
Load range indicates the tire’s maximum load-carrying capacity at a specific inflation pressure. Common load ranges include B, C, D, and E. Higher load ranges correspond to higher load capacities. Always match or exceed the original load range.
3. Can I use car tires on my trailer?
No, you should never use car tires on a trailer. Car tires are not designed to handle the loads and stresses associated with trailer use. Use only tires specifically designed for trailers (ST – Special Trailer tires).
4. What are ‘ST’ tires, and why are they important?
ST (Special Trailer) tires are designed specifically for trailer use. They have stiffer sidewalls to reduce sway and higher load-carrying capacities than car tires of the same size.
5. How does tire pressure affect my trailer’s performance?
Proper tire pressure is crucial for safe and efficient towing. Under-inflated tires can overheat and fail, while over-inflated tires can lead to a harsh ride and uneven wear. Always inflate your tires to the pressure recommended by the tire manufacturer.
6. What is ‘tire ply rating’, and how does it relate to load capacity?
Ply rating indicates the tire’s strength and load-carrying capacity. A higher ply rating generally indicates a stronger tire that can carry more weight. This is often expressed as a Load Range equivalent (B, C, D, E).
7. What is the difference between bias-ply and radial tires for trailers?
Bias-ply tires are less expensive and have stiffer sidewalls, making them suitable for heavier loads and rough terrain. Radial tires offer a smoother ride, better fuel economy, and longer tread life. Radials are increasingly common on trailers.
8. How often should I check my trailer tire pressure?
Check your trailer tire pressure before each trip and during long trips. Temperature changes can affect tire pressure. A tire pressure monitoring system (TPMS) can also be a good investment.
9. Can I mix different tire sizes or types on my trailer?
No, you should never mix different tire sizes or types on the same axle. Doing so can negatively affect handling and stability.
10. What should I do if my trailer tire blows out?
If a tire blows out, safely pull over to the side of the road. Engage your hazard lights and use warning triangles. Change the tire or call for roadside assistance. Avoid sudden braking or steering maneuvers.
11. How can I prevent trailer tire blowouts?
Prevent trailer tire blowouts by maintaining proper tire pressure, avoiding overloading, inspecting tires regularly for damage, and replacing tires when they reach their expiration date or show signs of wear. Consider using tire covers to protect tires from UV damage when the trailer is stored.
12. How do I read a trailer tire sidewall?
Understanding the markings on a trailer tire sidewall is crucial. Look for the tire size (e.g., ST205/75R15), load range, maximum load capacity, and maximum inflation pressure. The DOT code indicates the tire’s manufacturing date. For example, “DOT XX XX XXXX” where the last four digits indicate the week and year of manufacture. This is important because tires age, even if they have plenty of tread left.
By carefully considering these factors and consulting with professionals when needed, you can safely and effectively determine whether upsizing your trailer tires is the right choice for you. Remember that safety and performance should always be your top priorities.