Effective Gear Ratio Calculator
Understand how changing your tire size impacts your vehicle's effective final drive gear ratio and performance.
When you change the diameter of your tires, you're also altering your vehicle's effective final drive gear ratio. This calculator helps you quantify that change.
Understanding Effective Gear Ratio: The effective gear ratio determines how engine power is translated to the wheels. A numerically higher gear ratio (e.g., 4.10) provides more torque multiplication, leading to quicker acceleration but lower potential top speed and higher engine RPM at cruising speeds. A numerically lower gear ratio (e.g., 3.55, often called "taller" gearing) results in less torque multiplication (slower acceleration) but can offer a higher top speed and lower RPM at cruising speeds, potentially improving fuel economy.
How Tire Size Affects It: - Larger Tires: Installing tires with a larger overall diameter effectively makes your gear ratio numerically lower (taller gearing). Your engine will turn fewer revolutions for each tire rotation. - Smaller Tires: Installing tires with a smaller overall diameter effectively makes your gear ratio numerically higher (shorter gearing). Your engine will turn more revolutions for each tire rotation.
This tool is essential for anyone modifying their vehicle's tire size, whether for off-roading, performance enhancements, or aesthetics, to understand the resulting impact on performance characteristics.
- Enter the Overall Diameter (in inches) of your vehicle's original tires.
- Enter the Overall Diameter (in inches) of the new tires you are considering.
- Input your vehicle's current Axle Gear Ratio (e.g., 3.73, 4.10). This is usually found on a tag on the differential, in your owner's manual, or can be looked up by VIN.
- Click the "Calculate" button.
- The results will display the new Effective Gear Ratio and the percentage change, along with an explanation of its potential impact on performance (acceleration, cruising RPM).
All tools and information provided on TireCalculatorHub are for informational purposes only. Always consult with a qualified professional before making decisions about your vehicle's tires or modifications.
TireCalculatorHub is not liable for any damages or issues arising from the use of information or tools on this website.