Nitto NT555 255/45 R18 103Y

The Nitto NT555 is an all-season tire that provides excellent traction and handling in both dry and wet conditions. It is designed for high performance vehicles and provides a comfortable ride. The NT555 has a unique tread pattern that helps to reduce road noise and provides a smoother ride. It is also designed to provide excellent traction in both dry and wet conditions. The Nitto NT555 is a tire that is designed to be used in dry conditions.

What does 255/45R18 mean?


The tire width is 255mm.


The aspect ratio of the tire is 45. Aspect ratio is the relative height of tire sidewall. The number refers to the percentage of sidewall height in relation to tire width.


The letter in the middle refers to tire construction. Practically all tires sold for cars are radials.

Sometimes you also see tires with RF or ZR. RF indicates the tire is run flat, whereas ZR means the tire has speed rating higher than V. These tires are also radials, as the R indicates.


Rim diameter for the tire.

255/45R18 103Y tire size

The width of 255/45R18 103Y tire is stated in millimeters and sidewall height in percentages. In this table you’ll find out the 255/45R18 103Y tire size in inches as well as few additional metrics:

In inchesIn millimeters

Section Width


Sidewall height


Diameter / Height




Rim Diameter



746 per mile 464 per kilometer

Rim Size for 255/45R18 103Y Tires

Recommended rim sizes for 255/45R18 103Y tire:

DiameterWidth Range

What does 103Y mean?

The load index 103 means that the tire has been designed to support 1929 lbs or 875 kg.

The speed index Y means that the tire has been designed to be used in speed up to 186 mph or 300 kph.

This size tire is usually used on high-performance cars.


Nitto NT555 is a performance tire that offers excellent grip and handling. It is a great choice for those who want a tire that can provide a smooth, comfortable ride.

Tire Specification

Brand: Nitto
Model: NT555
Season: Summer
Size: 255/45 R18
Load Index: 103 — 875 kg | x4 - 3500 kg
Speed Index: Y — 300 km\h
Car Type:Passenger
Road: City
XL / Extra Load: No
RunFlat technology: No
Commercial / Reinforced: No