🛞

TIRE SIZE
COMPARISON SYSTEM

PRECISION FITMENT ANALYSIS

🚙 VEHICLE GARAGE

Select Vehicle

CURRENT SETUP

Factory Tire

265/70R17

NEW SETUP

Upgrade Tire

285/70R17

📊 Engineering Analysis

DIAMETER CHANGE

1.10"

31.61" →32.71"

GROUND CLEARANCE

+0.55"

Approximate height increase

WIDTH CHANGE

+20mm

Additional tire width

SPEEDOMETER

+2.1 mph

Actual speed at 60 mph indicated

⚠ FITMENT IMPACT

🟡 Check Clearance

Tire changes can affect clearance, gearing, acceleration, and handling.

🛞 Visual Tire Comparison

CURRENT

31.6"

265/70R17

+1.10"

Diameter Increase

NEW

32.7"

285/70R17

📘 TIRE SIZE GUIDE

How Tire Sizes Work

Tire sizes follow a simple format:

265/70R17

265

Tire width in millimeters.

70

Sidewall height percentage.

R17

Wheel diameter in inches.

❓ COMMON TIRE QUESTIONS

Tire Size Questions Explained

What does 265/70R17 mean?

The first number (265) is the tire width in millimeters. The second number (70) is the sidewall height as a percentage of the tire width. R17 means the tire fits a 17 inch wheel.

How much bigger is a 285/70R17 compared to a 265/70R17?

A 285/70R17 tire is approximately 1.1 inches taller and 20mm wider than a 265/70R17. This can increase ground clearance but may require additional clearance checks.

Will bigger tires affect my speedometer?

Yes. A taller tire travels farther with each rotation, causing your actual speed to be higher than the speed displayed on the speedometer.

Do larger tires reduce fuel economy?

Larger tires can reduce fuel economy because they are often heavier and require more energy to accelerate and rotate.

Do I need a lift for bigger tires?

It depends on the vehicle, tire size, wheel offset, and suspension setup. Always check clearance before upgrading.

🛠️ COMMUNITY REQUEST

Have a Tool Idea?

Have a calculator, guide, or topic you would like to see added to MechanixMatrix? Send us a request.

Request a Tool or Topic