Tire upgrading, or plus sizing, is a practice where performance-minded drivers upgrade their original equipment wheels with wider, bigger wheels. Why? It can make the vehicle look sportier. Plus, it offers better handling when done properly. There are two ways to plus-size:
- Plus 1, 2, Etc.
- Plus Zero
Plus 1, 2, Etc.
The most popular form of plus sizing is increasing your vehicle’s wheel diameter and your tire’s rim diameter. An example is changing from a 14” wheel to a 15” wheel. This is called “plus 1.” (Going from 14” to 16” is plus 2, etc.) To make plus-sizing work, the tire’s aspect ratio decreases while the wheel diameter increases. (Note: The overall diameter of the tire never changes, just the wheel diameter.)
If you want to leave your wheel diameter the same, you can still change to a wider tire. (Note: You may need a wider wheel as well.) An example is going from a P195/75R14 tire to P215/65R14 tire. What this means is that your tire width will be wider (195 millimeters to 215), your aspect ratio will be smaller (75 to 65) but the wheel diameter stays the same (14 and 14). Why do this? A wider contact patch on the road can mean better grip and handling.
What Is Staggering?
A staggered fitment is putting larger wheels on the back of your vehicle than the front of your vehicle. This specification comes from the vehicle’s manufacturer, and is designed to improve performance on vehicles with rear-wheel-drive. A dramatic example of staggering is a drag race car.
Very Important Plus-Sizing Legal:
Michelin does not recommend up-sizing due to safety reasons. If wheel diameter is increased too much, (from 14” to 17”, for example), or if a staggered fitment is used, then your anti-lock brakes, speedometer and stability system may not work properly. Some manufacturers have already tested and approved multiple wheel diameters, so be sure to ask your authorized Michelin tire dealer on any sizing needs.