35×12.5R17 vs 315/70R17 – SIZE/WEIGHT/HEIGHT/LOAD Difference

Understanding tire measurements can be a complex task, especially when tires of similar sizes are described using different measurements. The discrepancies between metric and imperial measurements can quickly become confusing. So what sets apart a 35×12.5R17 tire from a 315/70R17 tire?

Decoding the Measurements

The 35” tire measurement encompasses the overall combined width (mm), aspect ratio (%), and wheel diameter (inches). On the other hand, the 315 tire measurement is solely a metric value that represents the tire’s width in millimeters.

While the two sizes may appear similar, there are slight variations between tire models and brands. Let’s delve into the specific differences in size, weight, height, and load ratings.

35×12.5R17 vs 315/70R17 – Exploring the Differences

To begin, let’s analyze the 315/70R17 tire measurements. This tire is measured as follows:

  • 315: The tire width, measured in millimeters
  • 70: The tire aspect ratio (sidewall) height, measured as a percentage
  • 17: The tire’s wheel circumference, measured in inches

Now, let’s break down the 35×12.5R17 measurement:

  • 35: The overall tire size, including width, aspect ratio, and wheel diameter
  • 12.5: The section width, measured from the widest point of the outside sidewall to the widest point of the inner sidewall
  • 17: The wheel diameter, measured in inches

Differences in Size

When comparing the two tire sizes, the 315/70R17 measures approximately 12.4″ wide and 34.362″ tall. The 35×12.5R17, on the other hand, encompasses broader dimensions.

Weight Discrepancies

While these tire sizes may differ slightly in physical dimensions, other factors such as load ratings, tread patterns, and tire molds contribute to the overall weight difference. This variance can range from 500g to 1.1kg or 1.102 to 2.204 pounds.

Height Variances

In terms of aspect ratio (sidewall height), the 315/70R17 tire showcases a difference of approximately 3.8%. This aspect ratio affects the accuracy of speedometer readings.

Load Variances

The load range indicates the maximum weight that a tire can comfortably support. Contrary to popular belief, size and load rating are not closely related. 315/70R17 tires are available in various load rating options, such as C/D/E ranges. Higher load ratings offer improved load-carrying abilities but may sacrifice ride quality due to stiffer sidewalls and increased unsprung weight.

YMYL – Impact on Fuel Economy

Switching from 33” to 35” tires can result in a 1 to 2 mpg difference in fuel economy. The larger tire diameter, width, and circumference increase unsprung weight, directly affecting fuel efficiency, performance, gearing, and other drivetrain components. Actual mileage variations may differ depending on factors such as low-down torque and overall vehicle performance.

Metric Vs Mm – Understanding the Equivalence

While 315 wide tires and 35” tires may seem different, the truth is that 315 represents the tread width in millimeters, while 35″ represents the tire diameter. Therefore, 315/70/17 is commonly regarded as the metric equivalent size for standard/imperial 35-inch tires.


When comparing physical differences between these tire sizes, it is essential to note that most 35″ tires hardly reach the 34″ mark in actual tire size. When encountering a tire with both “315” and “35” measurements, it is crucial to examine load range and speed rating for the best fit in your specific application.


Related Articles

Back to top button