Can I Mount a 215/50/17 Tire on a Car When the Other 3 Are 215/45/17?

Mounting a 215/50/17 tire on your car while the other three tires are 215/45/17 is not recommended. Here are the reasons why, along with some insights into what you can do if you still want to proceed.

Diameter Difference

The 215/50/17 tire has a larger overall diameter than the 215/45/17 tire. Specifically, the 215/50/17 tire has an overall diameter of approximately 26.1 inches, while the 215/45/17 tire has an overall diameter of about 24.7 inches. This difference can lead to handling issues, particularly in terms of traction and stability.

Transmission and Differential Stress

Using tires of different diameters can cause undue stress on your vehicle's transmission and differential. This is especially true for all-wheel drive (AWD) or four-wheel drive (4WD) vehicles. Mismatched tire sizes can lead to mechanical failures, which could result in costly repairs or even safety hazards.

Handling and Safety

Having mismatched tires can affect the car's handling characteristics. This can lead to unpredictable behavior in corners or during braking, reducing the vehicle's overall stability and safety.

What You Can Do If You Still Want to Proceed

While it is generally not recommended to mix tire sizes, there are scenarios where this might be considered. For instance, if you are experiencing financial constraints and need to replace just one tire, you might need to compromise on tire uniformity.

Speedometer Inaccuracy

Pros such as Eagle, who owns a tire shop, mentioned that mounting the 215/50/17 tire would make the speedometer read low. This means that your speedometer would not accurately reflect your actual speed. Some may argue that this slight inaccuracy could be a margin of error that prevents you from receiving speeding tickets. However, it is crucial to be aware that such inaccuracy can also be dangerous, especially during driving in busy traffic or on high-speed roads.

Clearance and Fitting

For a general overview, it's highly likely that you will have clearance on a standard vehicle. If you have lowered the suspension, you might risk scrubbing the fender or bumper while turning. The 215/50 tires are about 0.85 inches taller than the 215/45 tires, which means you should double-check to ensure that your vehicle has enough clearance.

If you intend to turn the front wheels about 3/4 of the way, you can check the front bumper and the rear of the front fender to ensure that there is at least an extra half inch of clearance. For trucks, a common rule of thumb is to lift the truck 2 inches to clear a 1-inch taller tire. As long as your suspension is not lowered, you should be able to clear the taller tires easily. However, it's best to double-check to avoid any clearance issues.

Alternative Tires

A closer match would be a 245/40R17 tire. This tire size is within 0.4 inches of the circumference of the stock-sized tire. While the tire is 30mm (1.2 inches) wider, it is only 15mm (0.6 inches) on the inside and 15mm on the outside. This means that you might be able to find performance tires that fit this size. However, it is best to match all four tires with the exact size and brand for optimal performance and safety.

Considerations for Older Vehicles

If you drive an older vehicle without traction control or anti-lock brakes, you can mismatch your tires from front to rear as long as the tires physically fit. For example, if you have an older 1986 Chevy S10 with 38.5x14.50-15 tires in the rear and 31x12.50-15 tires up front, lifting the front suspension 3 inches more than the rear can help maintain a level stance.

Since the vehicle is 2WD, there is no need to worry about driveline binding in 4WD. Additionally, as it is older than ABS and traction control, computer controls are not a factor to consider. This setup can provide a unique and nostalgic driving experience while adhering to the principle of tire uniformity.

Conclusion

While you can mount a 215/50/17 tire on your car with 215/45/17 tires, it is important to consider the implications on your vehicle's performance, handling, and safety. Proper tire uniformity is essential for optimal driving and ensures that your vehicle operates efficiently and safely. If at all possible, it is recommended to match all four tires for the best results.