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May
The measurement is given in millimeters and all 4 tires must have the same width. The two-digit number after the slash mark in a tire size is the aspect ratio.
In this example the tire is 245 millimeters wide.
Meaning of tire size. Is the ratio of the height of the tires cross-section to its width. The two-digit number after the slash mark in a tire size is the aspect ratio. For example in a size P21565 R15 tire the 65 means that the height is equal to 65 of the tires width.
The bigger the aspect ratio the bigger the tires sidewall will be. There are two ways that tire manufacturers display tire size inches and metric. To find the tire size meaning in inches is very straight forward.
The first number is your overall diameter of the tire. In this example the tire diameter or height is 33 inches tall. Tire size specifications are outlined by the numbers and letters found on the sidewall of tires.
It is important that we understand tire geometry and be informed of the parameters that govern their performance. Tire sizes are defined by specifications such as the type width aspect ratio speed rating tire construction type and service description. 245 Section WidthTread mm The section width is the width of the tire from one sidewall to the other measured in millimeters.
In this example the tire is 245 millimeters wide. P-class tires include cars SUVs crossovers minivans and smaller pickup trucks. LT means light truck tire designed for vehicles that are towing trailers or have ¾- and 1-ton load capacity.
ST stands for Special Trailer. These tire sizes are meant for trailers including fifth wheels and other travel trailers boat trailers and utility trailers. C Commercial Example.
31x1050R15 C 109R Euro-Metric tire sizes ending with a C are commercial tires for use on delivery trucks and vans capable of carrying heavy loads. In addition to the C designation these sizes are also branded with a load range and service description rating load range B C or D. The aspect radio tells us which is the ratio of the tires width to its height.
For example a tire size of P22555 R15 tire the 55 means that the height is equal to 55 of the tires width. Letter R refers to how the tire was made. Almost all tires today are Radial tires which also the R stands for.
This number is a percentage that indicates the tires height vs. In the example above the aspect ratio of our tire is 65 meaning that this tires height is 65 of its width. These tires have an aspect ratio of 55 which means that the tires height is 55 percent of its width.
The larger this number the taller a tire is. The R here stands for radial which. The first number on a metric tire is the width in millimeters.
Divide this number by 254 to get the inch equivalent as there is 254 mm in 1 inch. The third number generally preceded by an R is the wheel diameter. The sidewall or aspect ratio are used in metric tire sizes to determine the overall height of a tire.
Tire diameter inches xxxyy1270zz where tire size is commonly written PxxxyyRzz on the sidewall. Note xxx is tread width in mm. Yy is aspect ratio sidewall height to tread width.
Zz is wheel diameter inches. The ISO Metric tire code consists of a string of letters and numbers as follows. The first number in a tires size say 225 is the width of the tire in millimeters.
This is pretty straight forward except that in the days of buying tires sized by the inch remember 311050x15 the first number was the height rather than the width. Back then it was inches not millimeters. But what does it mean when the tire says P24540ZR18.
For that you need to know a little bit about speed ratings. Speed ratings on tires are expressed in letters and are generally listed along with the load index for a tire after the size for instance. The 3-digit number before the slash denotes the tire width which is measured from sidewall to sidewall and corresponds to the tread that contacts the road.
The measurement is given in millimeters and all 4 tires must have the same width. For instance if the first number is 225 the tire tread is 225 mm wide. Tire size is an alphanumeric figure that lists a car tires dimensions.
This figure is part of the tire code which is found on a tires sidewall or doorjamb placard. Tire size codes include tire class width aspect ratio construction and wheel diameter. Here is a breakdown of each section.
Tire speed rating is communicated with the final letter in the tire service description and each letter translates to a specific top speed in miles per hour. Both speed rating and load index are part of a group of three digits at the tail end of the tire size information. Together these figures make up the tires service description.
For example appropriate tire widths for 60 rim are. 175 mm 185 mm 195 mm and 205 mm. The minimum tire width 175 mm designates the safe tire width 185mm and 195 mm are ideal tire widths and 205 mm is the maximum tire width.
The maximum tire width is not ideal because the tire tread is wider than the inside rim bead. Check your tires sidewallthe numbers there indicate your tire size roughly its outer diameter and its width but not always in that order. Typical mountain bike tire.
22 and 275 indicate a tire that has a width of 22 and an outer diameter of 275.