Plus sizing

Plus sizing is the practice of replacing an automotive wheel with one of a larger diameter fitted with a new tire of lower aspect ratio so that the new tire has the same diameter and circumference as the original tire to prevent any changes in speedometer accuracy, torque and traction control, while reducing sidewall flex and (generally) increasing cornerning ability.

The number following the "plus" describes the number of inches which is added to the diameter of the rim. For example, plus one sizing means increasing the wheel by one inch – from a 15 inch to a 16 inch, for example.

A "plus zero" upgrade means changing to a wider tire size while using the same diameter wheel.

Changing to a wider tire requires reducing the aspect ratio (the second number in the sequence of numbers that describes the tire's size). Since the aspect ratio is a percentage which is used to calculate the height of the tire's sidewall, if follows that if a larger number is used for the width, a smaller number must be substituted if the final result is to remain the same—which is the objective of Plus sizing.

Plus sizing example

Original tire Plus zero Plus one Plus two
195/65R15 205/60R15 215/55R16 225/45R17

These are simply examples and do not represent all of the possible combinations which could achieve the same result. For an R16 tire, 205/60, 225/55, 245/50 and 275/45 width/aspect ratio tires have essentially the same diameter.

The exact dimensions of tires in the same size might differ slightly depending on tire brand, model, etc.

Advantages

Disadvantages

Controversial issues

Some people claim larger wheels wear faster. Wheels with reduced sidewall heights may increase risk of damaged rims, breaking the bead, and/or damaged sidewalls. The increased width of the contact patch of wider tires may increase the risk of hydroplaning.

Plus sizing tires may enhance the vehicle's value. Improving the vehicle from the factory specifications may increase value.

The additional height and weight of plus sized wheels may reduce vulnerability to rollovers, particularly by changing the center of gravity. During rapid tire deflation at speed, reduced sidewall height may decrease rollovers.

Total wheel weight (tire & rim) is part of the unsprung weight of the vehicle and will have a great effect on traction while traveling over uneven terrain as the wheel can respond quicker (lighter weight) to terrain changes. This allows the wheel to get back on the ground more quickly.

See also

External links

References

This article is issued from Wikipedia - version of the 11/26/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.