Tire Size 285/70r17 in inches

Tire sizes can be confusing due to their alphanumeric designations, which may not provide an immediate understanding of their dimensions and specifications. This article will thoroughly explore the 285/70r17 tire size, providing a detailed breakdown of its dimensions in inches, relevant specifications, and overall performance.

285/70r17 in inches

Get a deep dive into tire size 285/70r17 in inches and learn how to convert from metric with our expert guide.

Feature Metric Inches
Overall Diameter 832 mm 32.8″
Tread Width 285 mm 11.2″
Rim Diameter 431.8 mm 17″
Sidewall Height 200 mm 7.9″
Circumference 2612.5 mm 103″
Revolutions 383 per km 615 per mile

285/70r17 Breakdown
The 285/70r17 tire size can be broken down into three main components:

  1. 285: This number represents the tread width in millimeters (285 mm), the width of the tire’s contact patch with the road. In inches, this is approximately 11.2″.
  2. 70: This number is the aspect ratio or the sidewall height expressed as a percentage of the tread width. In this case, the sidewall height is 70% of 285 mm, which is approximately 200 mm or 7.9 inches.
  3. R17: The “R” signifies radial construction, which offers better handling, longer tread life, and improved fuel efficiency. The “17” indicates the rim diameter in inches, meaning this tire is designed to fit a 17-inch wheel.

285/70r17 Alternative Size
It’s a good idea to pick replacement tires that have a diameter measurement that’s within 3% of your current ones, as a general rule.

Tire Size Overall Diameter Difference
235/80R17 31.8″ (808 mm) -2.9%
345/55R17 32″ (812 mm) -2.4%
255/75R17 32″ (814 mm) -2.2%
275/70R17 32.2″ (818 mm) -1.7%
305/65R17 32.6″ (828 mm) -0.5%
235/85R17 32.8″ (832 mm) 0%
255/80R17 33.1″ (840 mm) 1%
295/70R17 33.3″ (846 mm) 1.7%

Overall Diameter
The overall diameter, also known as tire height, is the total height of the tire when mounted on a wheel and inflated. For the 285/70r17 tire size, the overall diameter is 832 mm or 32.8 inches. 

This measurement is essential for calculating ground clearance, determining the space required within the wheel well, and ensuring the tire maintains the correct contact patch with the road.

Tread Width
Tread width refers to the width of the tire’s contact patch with the road. A wider tread width can provide better traction and handling, while a narrower tread width might offer improved fuel efficiency. The 285/70r17 tire size has a tread width of 285 mm, which translates to 11.2 inches.

Rim Diameter
The rim diameter is the diameter of the wheel on which the tire is mounted. The 285/70r17 tire size has a rim diameter of 431.8 mm or 17 inches, which means it is designed to fit a 17-inch wheel. This size is quite standard for trucks, SUVs, and off-road vehicles, providing ample strength and stability for these applications.

Sidewall Height
Sidewall height, or aspect ratio, is the height of the tire’s sidewall from the bead (where the tire meets the wheel) to the tread. The 285/70r17 tire size has a sidewall height of 200 mm, equivalent to 7.9 inches.

This tire size features a relatively high sidewall, contributing to better ride comfort and improved off-road performance by providing more cushioning against bumps and rough terrain.

Circumference
The tire circumference is the total distance around the outer edge of the tire. The circumference of the 285/70r17 tire is 2612.5 mm or 103 inches. This measurement is essential for calculating the tire’s revolutions per mile, which is directly related to the vehicle’s speedometer and odometer readings.

Revolutions
Revolutions per mile (or per kilometer) indicate how many times a tire rotates in one mile (or one kilometer) of travel. The 285/70r17 tire size has 383 revolutions per kilometer, translating to 615 revolutions per mile. 

This figure is crucial for ensuring accurate speedometer and odometer readings, as well as determining the effect of tire size changes on vehicle performance.

Tire Construction
The “R” in 285/70r17 signifies that the tire features radial construction. Radial tires have plies running radially from the center of the tire to its edges, providing improved handling, longer tread life, and better fuel efficiency compared to bias-ply tires. The tire’s construction impacts its overall performance, durability, and ride quality.

Is a 285/70r17 a 33 inch tire?

Yes, the 285/70R17 tire is approximately 32.72 inches in diameter, close to 33 inches. A 285/70R17 tire has a width of 285 millimeters, an aspect ratio of 70%, and fits on a 17-inch wheel. To determine the overall diameter of the tire in inches, we can follow these steps:

Calculate the sidewall height: Aspect ratio (70%) multiplied by the width (285mm) = 0.7 * 285 = 199.5mm
Convert sidewall height to inches: 199.5mm / 25.4 (1 inch = 25.4mm) ≈ 7.86 inches
Calculate the overall diameter: (Sidewall height * 2) + Wheel diameter = (7.86 * 2) + 17 ≈ 32.72 inches
So, a 285/70R17 tire is approximately 32.72 inches in diameter, which is close to 33 inches, but not exactly.

Our Observations
The 285/70r17 tire size features a relatively large overall diameter (32.8 inches) and tread width (11.2 inches), making it suitable for trucks, SUVs, and off-road vehicles. With a 17-inch rim diameter, these tires provide ample strength and stability for various applications.

The sidewall height (7.9 inches) offers a comfortable ride and improved off-road performance due to increased cushioning against bumps and rough terrain. The tire’s circumference (103 inches) and revolutions per mile (615) ensure accurate speedometer and odometer readings while also influencing vehicle performance.

With radial construction, the 285/70r17 tire size offers better handling, longer tread life, and improved fuel efficiency compared to bias-ply tires. Overall, this tire size is a popular choice for drivers seeking a balance of on-road comfort and off-road capability, particularly in trucks and SUVs.

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