tire size detail
(click for a tire code explanation)
When a tire size begins with a P, it signifies the tire is a p-metric size that was designed to be fitted on vehicles that are primarily used as passenger vehicles. This includes cars, minivans, sport utility vehicles and light duty pickup trucks (typically 1/4- and 1/2-ton load capacity). The use of p-metric sizes began in the late 1970s and they are the most frequently used type of tire size today.
Following the letter(s) that identify the type of vehicle and/or type of service for which the tire was designed, the three-digit numeric portion identifies the tire's section width/cross section in millimeters.
The 155 indicates that this tire is 155 millimeters across from the widest point when mounted and measured on a specified width wheel. Because many people think of measurements in inches, the 155mm can be converted to inches by dividing the width in millimeters by 25.4 (the number of millimeters per inch).
155mm / 25.4 = 6.10"
The ratio of the height of the tire's cross-section to it's width. 60 means that the height is equal to 60% of the tire's width.
Typically, following the three digits identifying the tire's width in millimeters is a two-digit number that identifies the tire's profile or aspect ratio.
The 60 indicates that this tire size's sidewall height (from rim to tread) is 50% of its width. The measurement is the tire's section height, and also referred to as the tire's series, profile or aspect ratio. The higher the number, the taller the sidewall. The lower the number, the lower the sidewall. We know that this tire size's section width is 155mm and that its section height is 50% of 155mm. By converting the 155mm to inches (155 / 25.4 = 6.10") and multiplying it by 50% (.50) we confirm that this tire size results in a tire section height of3.05".
The R in the 155/60R15 74T size identifies that the tire has a radial construction in which the tire's plies "radiate" out from the center of the wheel. Radial tires are by far the most popular type of tire today representing over 98% of all tires sold.
If the R in the size was replaced with a D (155/60R15 74T), it would identify that the internal tire body plies crisscross on a diagonal and that the tire has a "bias ply" construction. Tires using this construction are for light truck and spare tire applications.
The 15 indicates the tire and wheel diameter designed to be matched together.
Tires that have a rim diameter expressed in inches (155/60R15 74T, as well as8, 10, 12, 13,14,15, 17, 18, 19,20, 22, 23, 24,26 and 28) are called "inch rim" sizes. These are the most common types of tire sizes and are used on most cars, minivans, vans, sport utility vehicles and light duty light trucks.
Tires and wheels with unique rim diameters should never be combined with traditional "inch rim" tires and wheels.
The maximum speed that the tire can sustain for 10 minutes.
Today, the only tires that continue to include the speed rating "in" the tire size (155/60R15 74T) are Z-speed rated tires. In this case, following the two digits used to identify the aspect ratio are the letters ZR to identify the tire's speed rating (Z) and its internal construction (R). Since 1991, all other speed ratings are identified in the tire's Service Description.
When a tire size begins with a P, it signifies the tire is a p-metric size that was designed to be fitted on vehicles that are primarily used as passenger vehicles. This includes cars, minivans, sport utility vehicles and light duty pickup trucks (typically 1/4- and 1/2-ton load capacity). The use of p-metric sizes began in the late 1970s and they are the most frequently used type of tire size today.
Following the letter(s) that identify the type of vehicle and/or type of service for which the tire was designed, the three-digit numeric portion identifies the tire's section width/cross section in millimeters.
The 175 indicates that this tire is 175 millimeters across from the widest point when mounted and measured on a specified width wheel. Because many people think of measurements in inches, the 175mm can be converted to inches by dividing the width in millimeters by 25.4 (the number of millimeters per inch).
175mm / 25.4 = 6.89"
The ratio of the height of the tire's cross-section to it's width. 55 means that the height is equal to 55% of the tire's width.
Typically, following the three digits identifying the tire's width in millimeters is a two-digit number that identifies the tire's profile or aspect ratio.
The 55 indicates that this tire size's sidewall height (from rim to tread) is 50% of its width. The measurement is the tire's section height, and also referred to as the tire's series, profile or aspect ratio. The higher the number, the taller the sidewall. The lower the number, the lower the sidewall. We know that this tire size's section width is 175mm and that its section height is 50% of 175mm. By converting the 175mm to inches (175 / 25.4 = 6.89") and multiplying it by 50% (.50) we confirm that this tire size results in a tire section height of3.44".
The R in the 175/55R15 77T size identifies that the tire has a radial construction in which the tire's plies "radiate" out from the center of the wheel. Radial tires are by far the most popular type of tire today representing over 98% of all tires sold.
If the R in the size was replaced with a D (175/55R15 77T), it would identify that the internal tire body plies crisscross on a diagonal and that the tire has a "bias ply" construction. Tires using this construction are for light truck and spare tire applications.
The 15 indicates the tire and wheel diameter designed to be matched together.
Tires that have a rim diameter expressed in inches (175/55R15 77T, as well as8, 10, 12, 13,14,15, 17, 18, 19,20, 22, 23, 24,26 and 28) are called "inch rim" sizes. These are the most common types of tire sizes and are used on most cars, minivans, vans, sport utility vehicles and light duty light trucks.
Tires and wheels with unique rim diameters should never be combined with traditional "inch rim" tires and wheels.
The maximum speed that the tire can sustain for 10 minutes.
Today, the only tires that continue to include the speed rating "in" the tire size (175/55R15 77T) are Z-speed rated tires. In this case, following the two digits used to identify the aspect ratio are the letters ZR to identify the tire's speed rating (Z) and its internal construction (R). Since 1991, all other speed ratings are identified in the tire's Service Description.
(click for a tire code explanation)
When a tire size begins with a P, it signifies the tire is a p-metric size that was designed to be fitted on vehicles that are primarily used as passenger vehicles. This includes cars, minivans, sport utility vehicles and light duty pickup trucks (typically 1/4- and 1/2-ton load capacity). The use of p-metric sizes began in the late 1970s and they are the most frequently used type of tire size today.
Following the letter(s) that identify the type of vehicle and/or type of service for which the tire was designed, the three-digit numeric portion identifies the tire's section width/cross section in millimeters.
The 175 indicates that this tire is 175 millimeters across from the widest point when mounted and measured on a specified width wheel. Because many people think of measurements in inches, the 175mm can be converted to inches by dividing the width in millimeters by 25.4 (the number of millimeters per inch).
175mm / 25.4 = 6.89"
The ratio of the height of the tire's cross-section to it's width. 55 means that the height is equal to 55% of the tire's width.
Typically, following the three digits identifying the tire's width in millimeters is a two-digit number that identifies the tire's profile or aspect ratio.
The 55 indicates that this tire size's sidewall height (from rim to tread) is 50% of its width. The measurement is the tire's section height, and also referred to as the tire's series, profile or aspect ratio. The higher the number, the taller the sidewall. The lower the number, the lower the sidewall. We know that this tire size's section width is 175mm and that its section height is 50% of 175mm. By converting the 175mm to inches (175 / 25.4 = 6.89") and multiplying it by 50% (.50) we confirm that this tire size results in a tire section height of3.44".
The R in the 175/55R15 77T size identifies that the tire has a radial construction in which the tire's plies "radiate" out from the center of the wheel. Radial tires are by far the most popular type of tire today representing over 98% of all tires sold.
If the R in the size was replaced with a D (175/55R15 77T), it would identify that the internal tire body plies crisscross on a diagonal and that the tire has a "bias ply" construction. Tires using this construction are for light truck and spare tire applications.
The 15 indicates the tire and wheel diameter designed to be matched together.
Tires that have a rim diameter expressed in inches (175/55R15 77T, as well as8, 10, 12, 13,14,15, 17, 18, 19,20, 22, 23, 24,26 and 28) are called "inch rim" sizes. These are the most common types of tire sizes and are used on most cars, minivans, vans, sport utility vehicles and light duty light trucks.
Tires and wheels with unique rim diameters should never be combined with traditional "inch rim" tires and wheels.
The maximum speed that the tire can sustain for 10 minutes.
Today, the only tires that continue to include the speed rating "in" the tire size (175/55R15 77T) are Z-speed rated tires. In this case, following the two digits used to identify the aspect ratio are the letters ZR to identify the tire's speed rating (Z) and its internal construction (R). Since 1991, all other speed ratings are identified in the tire's Service Description.
When a tire size begins with a P, it signifies the tire is a p-metric size that was designed to be fitted on vehicles that are primarily used as passenger vehicles. This includes cars, minivans, sport utility vehicles and light duty pickup trucks (typically 1/4- and 1/2-ton load capacity). The use of p-metric sizes began in the late 1970s and they are the most frequently used type of tire size today.
Following the letter(s) that identify the type of vehicle and/or type of service for which the tire was designed, the three-digit numeric portion identifies the tire's section width/cross section in millimeters.
The 215 indicates that this tire is 215 millimeters across from the widest point when mounted and measured on a specified width wheel. Because many people think of measurements in inches, the 215mm can be converted to inches by dividing the width in millimeters by 25.4 (the number of millimeters per inch).
215mm / 25.4 = 8.46"
The ratio of the height of the tire's cross-section to it's width. 35 means that the height is equal to 35% of the tire's width.
Typically, following the three digits identifying the tire's width in millimeters is a two-digit number that identifies the tire's profile or aspect ratio.
The 35 indicates that this tire size's sidewall height (from rim to tread) is 50% of its width. The measurement is the tire's section height, and also referred to as the tire's series, profile or aspect ratio. The higher the number, the taller the sidewall. The lower the number, the lower the sidewall. We know that this tire size's section width is 215mm and that its section height is 50% of 215mm. By converting the 215mm to inches (215 / 25.4 = 8.46") and multiplying it by 50% (.50) we confirm that this tire size results in a tire section height of4.23".
The R in the 215/35R17 79H size identifies that the tire has a radial construction in which the tire's plies "radiate" out from the center of the wheel. Radial tires are by far the most popular type of tire today representing over 98% of all tires sold.
If the R in the size was replaced with a D (215/35R17 79H), it would identify that the internal tire body plies crisscross on a diagonal and that the tire has a "bias ply" construction. Tires using this construction are for light truck and spare tire applications.
The 17 indicates the tire and wheel diameter designed to be matched together.
Tires that have a rim diameter expressed in inches (215/35R17 79H, as well as8, 10, 12, 13,14,15, 17, 18, 19,20, 22, 23, 24,26 and 28) are called "inch rim" sizes. These are the most common types of tire sizes and are used on most cars, minivans, vans, sport utility vehicles and light duty light trucks.
Tires and wheels with unique rim diameters should never be combined with traditional "inch rim" tires and wheels.
The maximum speed that the tire can sustain for 10 minutes.
Today, the only tires that continue to include the speed rating "in" the tire size (215/35R17 79H) are Z-speed rated tires. In this case, following the two digits used to identify the aspect ratio are the letters ZR to identify the tire's speed rating (Z) and its internal construction (R). Since 1991, all other speed ratings are identified in the tire's Service Description.
smart Automobile (stylized and marketed as "smart") is a German automotive marque and division of Daimler AG, based in Böblingen, Germany. It ranges in microcars and subcompacts, primarily the Fortwo and Forfour with its primary assembly plants located in Hambach, France and Novo Mesto, Slovenia. Marketed in 46[2] countries in Asia, North and South America, Africa, Australia and Europe, production of the Fortwo had surpassed 1.7M units by early 2015.[3][4][5]
The design concept for the company's automobiles began at Mercedes-Benz in the early-70s and late-80s. After brief backing by Volkswagen, the first model was released by Daimler-Benz in October 1998. Several variants on the original design have been introduced, with the original being the "Fortwo".
smart derives from cooperation with Swatch and Mercedes: Swatch Mercedes ART. In its branding, the company lowercases its logotype and the logo incorporating a "c" and an arrow for "compact" and "forward thinking" respectively. All letters should be spelled out in lowercase as "Smart" is incorrect.