Understanding how different tire sizes affect your vehicle's performance is crucial when upgrading or replacing your wheels and tires. Our interactive calculator helps you compare any two tire sizes and visualize the real-world impact on your vehicle's handling, appearance, and speedometer accuracy.
Whether you're looking to plus-size for improved handling, downsize for better winter performance, or simply understand the differences between tire options, our calculator provides the precise measurements and expert analysis you need to make an informed decision.
The dimensions of your tires affect virtually every aspect of your vehicle's performance. A properly selected tire size maintains the correct overall diameter, ensuring your speedometer remains accurate and your vehicle handles as the manufacturer intended. Even small changes in tire dimensions can impact:
Use our calculator below to see exactly how a tire size change will affect your specific vehicle.
Compare different tire sizes and see how they affect your vehicle's performance, appearance, and speedometer accuracy
When changing tire sizes, your speedometer's accuracy may be affected. Use this calculator to see how your new tires will impact your speedometer readings.
Changing tire sizes can affect your vehicle's ground clearance. This calculator helps you visualize how your new tires will change your vehicle's ride height and clearance.
Below is a detailed comparison between your current tire size (225/45R17) and your new tire size (245/40R18). This analysis includes dimensional differences, performance impacts, and visual representation.
Your speedometer will read slightly lower than your actual speed. At highway speeds, this could mean you're traveling about 1-2 mph faster than indicated.
| Performance Aspect | Impact | Notes |
|---|---|---|
| Acceleration | Slight Decrease | Larger diameter increases the effective gearing ratio, potentially reducing acceleration. |
| Handling | Improved Response | Lower profile tires typically provide better steering response and cornering stability. |
| Ride Comfort | Slight Decrease | Reduced sidewall height offers less cushioning over bumps and rough surfaces. |
| Fuel Economy | Minimal Change | Diameter difference is within 3%, resulting in negligible impact on fuel economy. |
| Traction | Potentially Improved | Wider tread provides more rubber on the road, which can improve dry traction. |
This tire size change is within the recommended 3% diameter variance, making it a safe upgrade for your vehicle. The wider tread and lower profile will enhance handling response, while the minimal impact on speedometer accuracy won't require recalibration. Consider having your alignment checked after installing the new tires, as the different dimensions may slightly alter your suspension geometry.
Understanding how different tire sizes affect your vehicle's performance is crucial when upgrading or replacing your wheels and tires. Our interactive calculator helps you compare any two tire sizes and visualize the real-world impact on your vehicle's handling, appearance, and speedometer accuracy.
Whether you're looking to plus-size for improved handling, downsize for better winter performance, or simply understand the differences between tire options, our calculator provides the precise measurements and expert analysis you need to make an informed decision.
The dimensions of your tires affect virtually every aspect of your vehicle's performance. A properly selected tire size maintains the correct overall diameter, ensuring your speedometer remains accurate and your vehicle handles as the manufacturer intended. Even small changes in tire dimensions can impact:
Use our calculator below to see exactly how a tire size change will affect your specific vehicle.
Modern tire sizes use a standardized format that provides crucial information about their dimensions. For example, in a tire sized 225/45R17:
When comparing different tire sizes, all these dimensions work together to determine the tire's overall diameter, which is the most critical measurement to maintain when changing sizes.
For most vehicles, we recommend keeping changes in overall tire diameter within 3% of the original equipment specifications. This tolerance ensures:
For performance applications or off-road vehicles, different guidelines may apply. Our tire specialists can provide personalized recommendations for your specific vehicle and driving needs.
Your speedometer calculates speed based on the number of rotations your wheels make, assuming a specific overall tire diameter. Increasing tire diameter means fewer rotations for the same distance traveled, causing your speedometer to read slower than your actual speed. Conversely, decreasing tire diameter results in your speedometer reading faster than your actual speed. As a rule of thumb, a 3% increase in tire diameter causes approximately a 3% decrease in speedometer reading.
Plus-sizing involves increasing wheel diameter while decreasing tire sidewall height to maintain a similar overall tire diameter. For example, going from 225/60R16 to 225/45R17 is a plus-one upgrade. Plus-sizing typically improves handling response and cornering stability while maintaining proper speedometer calibration. However, the lower profile tires may provide a firmer ride and potentially increase the risk of wheel damage from potholes and road hazards.
While it's possible to install slightly wider tires on your stock wheels, there are limitations. Each wheel width has a range of acceptable tire widths. Generally, you can go up to 10-20mm wider than the original tire, depending on your wheel width. For example, a 7-inch wide wheel can typically accommodate tires from 195mm to 225mm wide. Installing tires that are too wide for your wheels can cause handling issues, uneven wear, and potential damage to the tire or wheel.
For most vehicles, we recommend keeping the overall tire diameter within 3% of the original equipment specifications. This range ensures your speedometer remains reasonably accurate and vehicle systems like ABS and traction control function properly. However, different applications may have different tolerances: performance vehicles may benefit from staying within 1-2% to preserve handling characteristics, while some off-road applications might accommodate differences up to 5% with proper modifications.
Yes, tire size changes can impact fuel economy in several ways. Larger diameter tires effectively increase your gear ratio, which can improve highway fuel economy but may reduce efficiency in city driving. Wider tires typically create more rolling resistance, which can decrease fuel economy regardless of driving conditions. Additionally, heavier wheels and tires require more energy to accelerate, further reducing efficiency. For maximum fuel economy, staying close to your vehicle's original tire specifications is generally best.
If your new tires are within 3% of the original diameter, recalibration is typically not necessary for most daily driving. However, for greater differences or if precise speed readings are important to you, speedometer recalibration is recommended. Many modern vehicles can be recalibrated using specialized diagnostic equipment that reprograms the vehicle's computer. Some vehicles may require physical speedometer gear changes. Check with our specialists to determine the appropriate solution for your specific vehicle make and model.
While our calculator provides accurate technical information, every vehicle is unique. Our tire specialists have years of experience with virtually every make and model, and can provide personalized recommendations based on your specific vehicle, driving habits, and performance goals.
Contact our wheel and tire experts today for personalized fitment advice and discover why we're the trusted authority for wheels and tires.
