Wondering what 315 70 R17 actually means in inches? This tire size designation might seem like a random string of numbers, but it reveals crucial dimensions that affect your vehicle’s performance, appearance, and handling.
When you’re upgrading your truck or SUV tires, understanding the exact measurements of a 315/70R17 tire can save you from costly mistakes. The numbers represent width, aspect ratio, and rim diameter—all essential factors in determining if these tires will fit your vehicle properly. Let’s break down what these measurements mean in standard inches and why they matter for your ride.
Understanding Tire Sizing: 315/70R17 Explained
Tire sizing codes like 315/70R17 follow a standardized format that conveys exact measurements about your tire. Breaking down this alphanumeric sequence reveals crucial information about the tire’s dimensions and construction type.
The first number, 315, indicates the tire’s width in millimeters from sidewall to sidewall. At 315mm wide, these tires are considerably broader than standard options, providing enhanced stability and traction for trucks and SUVs.
Following the width is the aspect ratio, represented by 70. This percentage tells you the tire’s sidewall height relative to its width—in this case, the sidewall height equals 70% of the 315mm width. Taller sidewalls like these typically offer better ride comfort and off-road capability.
The letter “R” identifies the tire’s construction type as Radial, the most common construction method in modern tires. Radial tires feature layers of cord running at 90-degree angles to the direction of travel, resulting in better road contact, improved fuel efficiency, and longer tread life.
The final number, 17, specifies the wheel diameter in inches. This measurement indicates the rim size the tire is designed to fit—a 17-inch wheel diameter in this example. Your replacement tires must match this number exactly to ensure proper fitment on your vehicle’s wheels.
Understanding these measurements helps you make informed decisions when purchasing new tires or upgrading your vehicle’s appearance and performance. Tire sizing directly impacts ground clearance, speedometer accuracy, and overall driving dynamics.
Converting 315/70R17 to Inches: Dimensions Breakdown
Converting tire measurements from metric to imperial units helps you better understand the actual size of your tires. The 315/70R17 tire size can be broken down into three primary dimensions in inches: overall diameter, section width, and sidewall height.
Overall Diameter in Inches
The overall diameter of a 315/70R17 tire measures approximately 34.4 inches from one end to the other. This measurement represents the total height of the tire when mounted on a wheel, measuring from the ground contact point to the top of the tire. The diameter significantly impacts your vehicle’s ground clearance, speedometer accuracy, and overall appearance. Many truck and SUV owners prefer this size for its impressive road presence and off-road capability.
Section Width in Inches
A 315/70R17 tire has a section width of about 12.4 inches. This measurement corresponds directly to the first number in the tire code (315 millimeters) converted to inches. The section width refers to the tire’s tread width from sidewall to sidewall when mounted on an appropriate rim. With its generous 12.4-inch width, this tire provides excellent stability and traction, particularly beneficial for larger vehicles requiring enhanced road grip and load-carrying capacity.
Sidewall Height in Inches
The sidewall height of a 315/70R17 tire equals approximately 8.7 inches. This dimension comes from the aspect ratio (70) in the tire size, indicating the sidewall height is 70% of the section width. For a 315mm wide tire, this calculates to about 221mm or 8.7 inches. Your tire’s sidewall height affects ride comfort, impact absorption, and handling characteristics. The relatively tall 8.7-inch sidewall on these tires offers good cushioning over rough terrain while maintaining sufficient responsiveness for everyday driving.
| Dimension | Measurement (inches) | Measurement (millimeters) |
|---|---|---|
| Overall Diameter | 34.4″ | 874 mm |
| Section Width | 12.4″ | 315 mm |
| Sidewall Height | 8.7″ | 221 mm |
| Wheel Diameter | 17″ | 431.8 mm |
How 315/70R17 Compares to Other Popular Tire Sizes
The 315/70R17 tire size stands out among popular options for trucks and off-road vehicles, offering exact performance characteristics based on its dimensions. These comparisons help you understand where this tire fits in the spectrum of available options and how it might affect your vehicle’s performance.
Comparing to Metric Alternatives
Metric tire alternatives provide different performance profiles compared to the 315/70R17. The 265/70R17 measures significantly smaller with a 31.6-inch diameter (2.8 inches less than the 315/70R17) and a 10.4-inch width (2 inches narrower). This size difference substantially impacts your vehicle’s ground clearance and stance, offering less aggressive appearance but potentially better fuel economy. Many truck owners find the 265/70R17 suitable for daily driving while sacrificing some of the off-road capability that comes with larger tires.
When mounted on appropriate wheels, the 315/70R17 fits rims between 8 and 10.5 inches wide for passenger applications, or up to 11 inches wide for light truck variants. These mounting specifications ensure proper tire bead seating and sidewall performance during various driving conditions.
Comparing to Standard Inch Sizes
The 35×12.50R17 represents the closest standard inch-sized alternative to the 315/70R17. This inch-designated tire measures 35 inches in diameter, making it approximately 0.6 inches taller than the 315/70R17’s 34.4-inch height. Your speedometer will read about 1.9% slower with these tires compared to the 315/70R17 due to this height difference.
Width measurements between these options remain similar, with the 35×12.50R17 measuring 12.5 inches across compared to the 315/70R17’s 12.4-inch width. The most notable difference appears in the sidewall height, where the 35×12.50R17 features an 11.5-inch sidewall compared to the 8.7-inch sidewall of the 315/70R17. Taller sidewalls typically provide additional flex for off-road performance but may feel less precise in on-road handling situations.
| Tire Size | Section Width (in.) | Overall Diameter (in.) | Wheel Size (in.) | Sidewall Height (in.) |
|---|---|---|---|---|
| 315/70R17 | 12.4 | 34.4 | 17 | 8.7 |
| 35×12.50R17 | 12.5 | 35.0 | 17 | 11.5 |
| 265/70R17 | 10.4 | 31.6 | 17 | 7.3 |
The 315/70R17 offers a balanced option between these alternatives, providing substantial ground clearance and traction without requiring the extensive vehicle modifications often needed for 35-inch tires. Each revolution of a 315/70R17 tire covers approximately 107.9 inches, resulting in about 587 revolutions per mile traveled.
Benefits and Applications of 315/70R17 Tires
The 315/70R17 tire size offers many advantages for both off-road enthusiasts and daily drivers. These tires deliver exceptional performance across various terrains while maintaining reasonable on-road manners, making them a popular choice for trucks and SUVs.
Off-Road Performance Advantages
Ground clearance increases significantly with the 34.4-inch overall diameter of 315/70R17 tires, allowing your vehicle to navigate over rocks, logs, and uneven terrain with ease. The impressive 12.4-inch width creates a broader footprint that enhances flotation on soft surfaces like mud, sand, and snow, providing superior traction when you need it most. Deep treads and aggressive patterns, featured on models such as the Goodyear Wrangler Territory LT315/70R17, grip effectively on challenging surfaces including loose gravel, slippery rocks, and muddy trails. The generous 8.7-inch sidewall height absorbs impacts from rough terrain, protecting your wheels and improving ride comfort during off-road adventures.
On-Road Handling Characteristics
Stability improves noticeably with 315/70R17 tires thanks to their wider profile, giving you more confident cornering and better traction on wet pavement. Braking distances can decrease on dry surfaces due to the increased rubber contact patch, improving safety during emergency stops. Fuel economy typically drops by 1-2 mpg compared to smaller tire options because of increased rolling resistance and additional rotational mass. Acceleration performance may decrease slightly as your vehicle’s drivetrain works harder to rotate these larger, heavier tires. Speedometer accuracy decreases by approximately 8% with these larger tires, meaning your actual speed is faster than what’s displayed unless recalibrated. Road noise increases moderately compared to standard tires, especially with aggressive tread patterns designed for off-road use. Comfort on highways remains adequate but firmer than with smaller options like 265/70R17 tires, trading some on-road plushness for superior off-road capability.
Selecting the Right 315/70R17 Tires for Your Vehicle
315/70R17 tires are popular choices for trucks and SUVs because of their wide footprint and moderate sidewall height. These tires offer an excellent balance of traction, ride comfort, and off-road capability while their substantial 12.4-inch width delivers enhanced grip and stability on various surfaces. The radial construction improves fuel efficiency and extends tread life compared to older tire designs.
Top Brands and Models
Goodyear Wrangler Territory LT315/70R17 stands out among the options in this size category with its aggressive tread patterns that excel on mud, rocks, and gravel. These tires handle off-road adventures confidently while maintaining reliable performance on highways for everyday driving. Several other reputable manufacturers produce quality options in this size, including BFGoodrich, Michelin, Falken, and Toyo. Each brand typically offers specialized tires for both all-terrain applications and more extreme mud-terrain conditions, letting you match your tire choice to your exact driving needs.
Price Range and Value Considerations
315/70R17 tires typically cost between $200 and $350 per tire, with prices varying based on brand reputation, tread design, and technology features. Premium brands with higher-quality rubber compounds and advanced tread patterns often justify their higher price tags through improved durability and performance, particularly for vehicles frequently used off-road or carrying heavy loads. Customer reviews provide valuable insights into real-industry performance, while warranty coverage can significantly affect the overall value proposition of different tire models. The investment in quality tires pays dividends through better traction, handling, and longevity compared to budget alternatives.
Conclusion
The 315/70R17 tire size offers a perfect balance for truck and SUV owners seeking enhanced off-road capability without sacrificing on-road performance. At approximately 34.4 inches in diameter and 12.4 inches wide these tires provide important ground clearance and traction while maintaining reasonable handling characteristics.
When shopping for these tires remember to consider your exact driving needs and budget. Quality options from reputable manufacturers will cost between $200-$350 but offer superior durability and performance benefits that justify the investment.
By understanding what these numbers mean you’ll make more informed decisions about your vehicle’s setup ensuring the perfect combination of appearance functionality and driving experience for your truck or SUV.
Frequently Asked Questions
What does the tire size 315/70R17 mean?
The tire size 315/70R17 represents three key measurements: 315 indicates the width in millimeters (12.4 inches), 70 is the aspect ratio (sidewall height is 70% of the width), R stands for Radial construction, and 17 is the rim diameter in inches. This combination creates a tire with approximately 34.4 inches of overall diameter, offering excellent ground clearance and off-road capability.
How does a 315/70R17 tire compare to standard truck tires?
Compared to common truck tires like the 265/70R17 (31.6-inch diameter, 10.4-inch width), the 315/70R17 is significantly wider and taller at 34.4 inches. This provides better ground clearance and traction but may affect fuel economy. It’s similar to a 35×12.50R17 tire but slightly shorter, offering a good balance of off-road capability without requiring extensive vehicle modifications.
Will 315/70R17 tires affect my vehicle’s performance?
Yes, these tires will impact performance in several ways. Off-road, they provide increased ground clearance and better traction on challenging terrain. On-road, they improve stability but may slightly decrease fuel economy and acceleration. They can also affect speedometer accuracy and increase road noise, though comfort remains adequate for highway driving.
How much do 315/70R17 tires typically cost?
Quality 315/70R17 tires typically range from $200 to $350 per tire, depending on the brand, tread pattern, and performance features. Premium brands with advanced technologies for off-road performance may cost more. While budget options exist, investing in quality tires is recommended for better durability and performance, especially for off-road use or carrying heavy loads.
What vehicles can use 315/70R17 tires?
These tires are primarily designed for trucks and SUVs that can accommodate their large size. Popular vehicles include Ford F-150/F-250, Chevy Silverado, Ram 1500, Jeep Wrangler, Toyota Tacoma, and similar full-size trucks and off-road-oriented SUVs. Vehicle compatibility depends on wheel well clearance and suspension setup, and some vehicles may require modifications like leveling kits.
Will I need to modify my vehicle to fit 315/70R17 tires?
Many trucks and SUVs will require some modifications to properly fit 315/70R17 tires. Common modifications include lift kits (2-3 inches), leveling kits, wheel spacers, and possibly fender trimming to prevent rubbing. The exact modifications needed depend on your specific vehicle make and model. Always consult with a professional to ensure proper fitment.
What are the best brands for 315/70R17 tires?
Top brands for 315/70R17 tires include BF Goodrich (KO2), Goodyear (Wrangler Territory), Nitto (Ridge Grappler), Toyo (Open Country), Falken (Wildpeak), and Cooper (Discoverer). These manufacturers offer various tread patterns optimized for different conditions, from aggressive all-terrain designs to mud-terrain patterns for extreme off-road use, with excellent durability and performance.
How long do 315/70R17 tires typically last?
With proper maintenance, quality 315/70R17 tires typically last 40,000-60,000 miles for all-terrain models and 30,000-50,000 miles for mud-terrain versions. Lifespan varies based on driving conditions, maintenance practices, and tire rotation schedule. Off-road use, heavy loads, and improper inflation will reduce longevity. Most manufacturers offer treadwear warranties ranging from 40,000-50,000 miles.
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