How to Do Plus Sizing on Wheel and Tire Combinations
- 1). Understand the pros and cons of plus sizing wheels and tires. The good thing about using smaller tires and larger diameter wheels is it keep the speedometer accurate. There also increases handling and torque. However, it does make for a rougher ride and tends to wear the tires faster.
- 2). Know what plus size you are. There is generally plus sizing one and plus sizing two. A one would be when you make the transition from, say, a 16" to 17" wheel, whereas a two plus sizing would be from a 16" to an 18". The plus size number is essentially the difference in inches between the old wheels and the new wheels.
- 3). Keep the tire aspect ratio as close as you can when plus sizing, this will keep the tread wear close to normal and extend the length of the tires. To calculate the aspect ration you currently have: E = (A * B)/25.4mm (resulting in inches). B= the percentage of aspect ratio, this can be found on the side of the tire. For example, 225/55R-16. The 55R is the aspect ratio of 55%. Converting it to inches, allows you to do the same with the new tires and make sure they are similar.
- 4). Work with a tire specialist if you are having trouble finding the right tires for your new wheels. It's better to get help than to end up with less than optimal tires and have them wear faster than normal, costing you additional time and money.