close
close
what is 315 in tire size

what is 315 in tire size

3 min read 05-02-2025
what is 315 in tire size

Decoding tire sizes can feel like deciphering a secret code. But understanding the numbers, like what a 315 tire size means, is crucial for maintaining your vehicle's performance and safety. This article breaks down the 315 tire size, explaining what the numbers represent and what to expect from this type of tire.


What Does 315 Mean in Tire Size?

The "315" in a tire size designation refers to the tire's section width. This is the measurement in millimeters of the tire's tread width from sidewall to sidewall when mounted on a wheel. A 315 tire is therefore very wide—315 millimeters, to be exact. This signifies a large contact patch with the road, impacting handling, traction, and performance. This width is typically found on high-performance vehicles, trucks, and SUVs.


More Than Just Width: Understanding the Full Tire Size

The "315" is only part of the equation. A complete tire size designation, like "315/35R20," includes additional critical information:

  • 315: Section width (as discussed above).
  • 35: Aspect ratio. This is the ratio of the tire's sidewall height to its section width, expressed as a percentage. A 35 aspect ratio means the sidewall height is 35% of the section width (315mm). Lower aspect ratios mean shorter, stiffer sidewalls, leading to improved handling and responsiveness but a harsher ride.
  • R: Construction type. "R" indicates a radial tire construction, the most common type used in modern vehicles. Radial tires have stronger sidewalls and better fuel economy compared to bias-ply tires.
  • 20: Wheel diameter. This is the diameter of the wheel rim, measured in inches. A 20-inch wheel requires a tire designed to fit that specific size.

Characteristics of 315 Tires

Because of their wide section width and often low aspect ratio, 315 tires offer specific characteristics:

  • High-Performance Handling: The large contact patch provides excellent grip and responsiveness, particularly beneficial for high-speed driving and cornering.
  • Increased Traction: The wider footprint enhances traction, especially in wet or slippery conditions.
  • Improved Stability: Larger tires contribute to a more stable ride, particularly at higher speeds.
  • Potentially Harsher Ride: The stiffer sidewalls associated with lower aspect ratios can result in a less comfortable ride, transmitting more road imperfections to the vehicle's cabin.
  • Greater Rolling Resistance: Wider tires generally experience slightly increased rolling resistance, which can slightly reduce fuel efficiency.

Vehicles That Use 315 Tires

315 tires are typically fitted to high-performance vehicles, luxury cars, SUVs, and light trucks. These vehicles often have larger wheel wells to accommodate such wide tires. Always check your vehicle's owner's manual to verify the correct tire size for your specific model. Using the wrong tire size can impact handling, braking, and overall vehicle safety.


Choosing the Right 315 Tire

Choosing the right 315 tire involves considering several factors beyond just the size:

  • Tire Compound: Different rubber compounds offer varying levels of grip, wear resistance, and performance in different weather conditions.
  • Tread Pattern: The tread pattern influences traction, noise levels, and hydroplaning resistance.
  • Load Index and Speed Rating: These ratings indicate the maximum load the tire can carry and its maximum safe speed, respectively. These must match or exceed your vehicle's requirements.

Before purchasing any tires, always consult your vehicle’s owner’s manual or a tire professional to ensure you select the appropriate size and specifications for your vehicle and driving style.


Conclusion

A 315 tire size denotes a wide tire with significant implications for handling, traction, and ride quality. Understanding the complete tire size designation—including section width, aspect ratio, construction type, and wheel diameter—is crucial for making informed decisions about your vehicle's tires. Remember to always prioritize safety and consult with a tire professional or your vehicle's owner's manual for guidance. Proper tire selection ensures optimal performance, safety, and longevity.

Related Posts