Tyre Tips

Why is my Tyre Size different from the original? Explaining Zero Plus, One Plus and Two Plus Sizing

Have you ever been to a tyre shop looking for a specific size and the uncle tells you to take this one because “it’s the same one”? Although it sounds alarming, uncle is half wrong and half right!

The more accurate term is “Zero Plus Sizing”, which means that you are changing the profile and width of the tyre without changing the rim size.

photo credit: blackcircles

When you Zero Plus Size your tyres, what happens is that it creates a larger contact patch (width of your tyres) and a shorter sidewall (the side of your tyre).

Photo Credit: Tirerack

The tyre on the left is a 205/55R16 and the tyre on the right is a 225/50R16.

After this is done, it results in a few effects:

Advantages of Zero Plus SizingDisadvantages of Zero Plus Sizing
Increased Steering ResponseLess Shock Absorption
Improved Dry HandlingSlightly Increased Fuel Consumption
Aggressive Aesthetics Higher Risk of Hydroplaning
Enhanced CorneringIncreased Wheel Damage Risk
More Stability

A more detailed guide on the advantaged and disadvantages of plus sizing can be found on the US popular mechanics website.

You can also check websites like tiresize.com to check out some of the “Zero Plus” equivalent sizes that you can use.

Photo Credit: Tiresize.com

One Plus & Two Plus Sizing

More commonly, many people choose to upsize their wheels by changing 16″ to 17″/18″, etc. One, two or three plus sizing happens when you increase 1″/2″/3″ for the wheel, and decrease 1″/2″/3″ respectively for the tyre. The height of the tyre and wheel remains the same after upsizing.

Photo Credit: Popular Mechanics

Although this is simple in principle, there are many ways where this can go wrong 😱 For example, when the tyre diameter is smaller or larger than the original equipment (OE) tyre, you will get a speedometer error (i.e. your car may be going slower/faster than shown on the speedometer). You can calculate the error on websites such as tyresizecalculator.com.

We hope this has been an informative article on tyre sizes and feel free to message us on Facebook or Whatsapp +6592479969 if you have any other questions 👍🏻

Cheers,

Cordillia from Pitstop Tyres