Yokohama

Customizing


Plus Sizing

"Inch Up" To Plus Zero, Plus One &
Plus Two Tire Size Applications








What's "Inch Up"?

 

Why "Inch Up"?

"Inch Up" is the process of mounting a lower aspect ratio tire and larger diameter wheel on your car. This creates a larger contact patch and a shorter sidewall.

 

"Inch Up" to improve your vehicle's performance and appearance.

  • Increased Steering Response
  • Improved Dry Handling
  • Enhanced Cornering Ability
  • Aggressive Good Looks

Lug-centric wheels require extra care in mounting on a vehicle. When using shouldered nuts instead of tapered nuts, take extra care to properly locate the wheel. Never use air tools to install high performance wheels! Always use a torque wrench and follow accepted tightening procedures.

High Performance Wheels

"Inch Up" to improve your vehicle's performance and appearance.

Plus Zero
This method utilizes the same wheel diameter as OE, but incorporates a tire with a larger than OE section width and smaller than OE aspect ratio. For example, replacing an OE 175/70R14 tire (on a 5.5-inch wheel) with a 195/60R14 tire would be a proper Plus Zero fitment. Note that this may require a replacement wheel to maintain proper rim width for the new tire.

Plus One
This method utilizes a one-inch larger diameter wheel, in conjunction with a tire of a one-step lower aspect ratio. An example of an appropriate Plus One fitment is to replace an OE 175/70R13 tire (23-inch overall diameter) with a 185/60R14 tire (22.9-inch overall diameter). Note that this method always requires a replacement wheel.

Plus Two
This method utilizes a two-inch larger diameter wheel, in conjunction with a tire of a two-step lower aspect ratio. An example of an appropriate Plus Two fitment is to replace an OE 175/70R13 tire (23-inch overall diameter) with a 195/50R15 tire (22.8-inch overall diameter).

An independent research company recently conducted a test to determine the effect Inch Up has on handling. Included here is an abbreviated summary of the test results.

The vehicle used for this comparison was a 1989 Mazda RX-7 SE. The original equipment tire is a 185/70HR14, and is mounted on a 5.5-inch wide wheel. The test was conducted on a dry asphalt surface. As the results from the lateral acceleration and handling course indicate, each successive plus size led to a noticeable increase in handling performance.

This fitment guide recommends several Inch Up applications for both import and domestic vehicles. If the desired Inch Up application is not listed, the guidelines listed on the next page should be utilized to evaluate its appropriateness.

Warning:
When changing to a non-OE tire size, always consult the load/inflation charts to determine proper inflation pressure to maintain OE load-carrying capacity.