Tire and wheel size guides
Before you change sizes, these guides explain what changes and what to check.
- Plus sizing wheels: bigger rims, same overall heightYou can usually fit a wheel one or two inches larger if the tire's sidewall gets shorter, so the overall diameter stays within about 3% of the original. That is plus sizing: 205/55R16 becomes 225/45R17 (+0.38%) or 225/40R18 (+0.84%).
- The 3% tire size ruleThe 3% rule says a replacement tire should stay within 3% of the original overall diameter. In the United States it is a guideline used by tire shops and wheel makers, not a federal law. It keeps the speedometer, gearing, ABS and stability control close to how the vehicle was calibrated.
- 33-inch tire in metricA 33 in tire is 838.2 mm tall on paper. The closest metric sizes are 285/75R16 (32.83 in), 285/70R17 (32.71 in), 275/70R18 (33.16 in) and 275/60R20 (32.99 in). They are commonly sold as 33s, and real 33s from most brands measure about 32.5 to 32.9 in anyway.