75/5R9 Tire Size Calculator

Complete specifications and dimensions for 75/5R9 tire size

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75
5
9

75/5R9 Quick Specifications

75mm
Section Width
3.8mm
Sidewall Height
9.3"
Overall Diameter
2170
Revs per Mile

How to Read 75/5R9 Tire Size? What Does 75/5R9 Mean?

Let's break down the tire size 75/5R9 to understand what each number and letter means:

75 (Section Width)

The first number "75" represents the tire's width in millimeters, measured from sidewall to sidewall. In this case, the tire is 75 millimeters wide (approximately 2.95 inches).

5 (Aspect Ratio)

The number "5" after the forward slash is the aspect ratio or profile. This means the tire's sidewall height is 5% of its width. For a 75mm wide tire, the sidewall height would be3.75mm (approximately 0.15 inches).

R (Construction)

The letter "R" indicates this is a Radial tire, which is the most common type of tire construction today. Radial tires have layers of cord that run radially (at 90 degrees) from the center of the tire.

9 (Wheel Diameter)

The last number "9" specifies the wheel diameter in inches. This means the tire is designed to fit a 9-inch wheel. The total diameter of the tire would be the wheel size plus twice the sidewall height.

Detailed Measurements for 75/5R9

Based on the 75/5R9 tire size, here are the calculated measurements:

  • Total Tire Diameter: 9 inches (wheel) + 2 × 0.15 inches (sidewall height) = 9.30 inches
  • Sidewall Height: 3.75mm or 0.15 inches (on each side)
  • Circumference: Approximately 29.20 inches (based on π × total diameter)
  • Revolutions per Mile: About 2170 (varies slightly based on load and air pressure)

Key Tire Measurements Explained

Section Width

The width of the tire from sidewall to sidewall, measured in millimeters. For 75/5R9, this is 75mm or approximately 2.95 inches.

Aspect Ratio

The height of the tire's sidewall as a percentage of the width. A 5 aspect ratio means the sidewall height is 5% of the tire's width.

Overall Diameter

The total height of the 75/5R9 tire when mounted on the wheel is 9.30 inches. This includes both the wheel diameter and the tire's sidewall height on both sides.

Sidewall Height

For 75/5R9, the sidewall height is 3.75mm (0.15 inches). This is the distance from the wheel rim to the outer edge of the tire.

Why Accurate Tire Measurements Matter

  • Vehicle Performance: Tire size affects your vehicle's acceleration, braking, and handling characteristics.
  • Speedometer Accuracy: Changes in tire diameter can affect your speedometer and odometer readings.
  • Clearance Issues: Incorrect tire sizes may cause rubbing against your vehicle's fenders or suspension components.
  • Fuel Economy: Larger or heavier tires can impact your vehicle's fuel efficiency.

Pro Tips for 75/5R9 Tires

✓ Check Your Vehicle's Manual: Always consult your vehicle's manual to confirm 75/5R9 is the correct size for your vehicle.

✓ Consider Your Usage: The 75/5R9 size may be better suited for specific uses (highway driving, off-road, performance, etc.).

✓ Maintain Proper Sizing: Keep front and rear tire sizes consistent unless specifically recommended otherwise by your vehicle manufacturer.

✓ Watch for Clearance: When using 75/5R9 tires, ensure adequate clearance for steering, suspension, and body components.

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