# 2008 BMW Z4 Tire Size

Your BMW was manufactured with different tire sizes. To determine the best tire size for your specific 2008 BMW Z4, we first need to determine your rim size. Please review the information below.

## How to Determine Rim Size

Check your existing tires. Your BMW Z4's rim size is the number to the right of the R. In the example pictured here, the tire size fits 16-inch rims.

## Rim Size Selection

Now that you know your rim size, make a selection below to filter your results.

## 17-Inch Rims

### 2008 BMW Z4

There are multiple tire sizes for your 2008 BMW Z4 that depend upon the trim level. Look for your trim level below to get a color-coded explanation of your tire size. Then pick the best tire size for your 2008 BMW Z4.

Trim Options:

### Coupe 3.0siRoadster 3.0iRoadster 3.0si

## 225/45R17 91

### Simplified Size: 225-45-17

Simplified size is useful for shopping and buying tires.

The original tire size for your 2008 BMW Z4 is **225/45R17 91W**. A color-coded explanation of the 2008 BMW Z4's tire size is shown below.

225 | This number indicates that your tire has a width of 225 millimeters. | ||||||

45 | This number means that your tire has an aspect ratio of 45%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 45% of the width. In this case, the sidewall height works out to be 101 millimeters. | ||||||

R | This letter denotes how your tire was constructed. Radial is the standard construction method for about 99% of all tires sold today.
| ||||||

17 | The tire size was designed to fit rims or wheels that are 17 inches in diameter. | ||||||

91 | This tire has a load index of 91, which means it's capable of carrying a load of 1353 pounds (615 kg) or less. A higher number means the tire can carry more weight. A lower number means the opposite. | ||||||

This tire has a speed rating of W, which means 167 mph (270 km/h) is the maximum speed that can be sustained for 10 minutes. A higher speed becomes dangerous. |

Trim Options:

### Roadster 3.0i w/Sport Pkg.

## 225/45R17 91(Front)

### Simplified Size: 225-45-17

Simplified size is useful for shopping and buying tires.

The original tire size for your 2008 BMW Z4 is **225/45R17 91W (Front)**. A color-coded explanation of the 2008 BMW Z4's tire size is shown below.

225 | This number indicates that your tire has a width of 225 millimeters. | ||||||

45 | This number means that your tire has an aspect ratio of 45%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 45% of the width. In this case, the sidewall height works out to be 101 millimeters. | ||||||

R | This letter denotes how your tire was constructed. Radial is the standard construction method for about 99% of all tires sold today.
| ||||||

17 | The tire size was designed to fit rims or wheels that are 17 inches in diameter. | ||||||

91 | This tire has a load index of 91, which means it's capable of carrying a load of 1353 pounds (615 kg) or less. A higher number means the tire can carry more weight. A lower number means the opposite. | ||||||

This tire has a speed rating of W, which means 167 mph (270 km/h) is the maximum speed that can be sustained for 10 minutes. A higher speed becomes dangerous. |

Trim Options:

### Roadster 3.0i w/Sport Pkg.

## 255/40R17 94(Rear)

### Simplified Size: 255-40-17

Simplified size is useful for shopping and buying tires.

The original tire size for your 2008 BMW Z4 is **225/45R17 91W (Front)**. A color-coded explanation of the 2008 BMW Z4's tire size is shown below.

255 | This number indicates that your tire has a width of 255 millimeters. | ||||||

40 | This number means that your tire has an aspect ratio of 40%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 40% of the width. In this case, the sidewall height works out to be 102 millimeters. | ||||||

R | This letter denotes how your tire was constructed. Radial is the standard construction method for about 99% of all tires sold today.
| ||||||

17 | The tire size was designed to fit rims or wheels that are 17 inches in diameter. | ||||||

94 | This tire has a load index of 94, which means it's capable of carrying a load of 1474 pounds (670 kg) or less. A higher number means the tire can carry more weight. A lower number means the opposite. | ||||||

This tire has a speed rating of W, which means 167 mph (270 km/h) is the maximum speed that can be sustained for 10 minutes. A higher speed becomes dangerous. |

## 18-Inch Rims

### 2008 BMW Z4

There are multiple tire sizes for your 2008 BMW Z4 that depend upon the trim level. Look for your trim level below to get a color-coded explanation of your tire size. Then pick the best tire size for your 2008 BMW Z4.

Trim Options:

### Coupe 3.0si w/Sport Pkg.Roadster 3.0si w/Sport Pkg.

## 225/40R18 88(Front)

### Simplified Size: 225-40-18

Simplified size is useful for shopping and buying tires.

The original tire size for your 2008 BMW Z4 is **225/40R18 88W (Front)**. A color-coded explanation of the 2008 BMW Z4's tire size is shown below.

225 | This number indicates that your tire has a width of 225 millimeters. | ||||||

40 | This number means that your tire has an aspect ratio of 40%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 40% of the width. In this case, the sidewall height works out to be 90 millimeters. | ||||||

R |
| ||||||

18 | The tire size was designed to fit rims or wheels that are 18 inches in diameter. | ||||||

88 | This tire has a load index of 88, which means it's capable of carrying a load of 1232 pounds (560 kg) or less. A higher number means the tire can carry more weight. A lower number means the opposite. | ||||||

Trim Options:

### Coupe 3.0si w/Sport Pkg.Roadster 3.0si w/Sport Pkg.

## 255/35R18 90(Rear)

### Simplified Size: 255-35-18

Simplified size is useful for shopping and buying tires.

The original tire size for your 2008 BMW Z4 is **225/40R18 88W (Front)**. A color-coded explanation of the 2008 BMW Z4's tire size is shown below.

255 | This number indicates that your tire has a width of 255 millimeters. | ||||||

35 | This number means that your tire has an aspect ratio of 35%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 35% of the width. In this case, the sidewall height works out to be 89 millimeters. | ||||||

R |
| ||||||

18 | The tire size was designed to fit rims or wheels that are 18 inches in diameter. | ||||||

90 | This tire has a load index of 90, which means it's capable of carrying a load of 1320 pounds (600 kg) or less. A higher number means the tire can carry more weight. A lower number means the opposite. | ||||||

Trim Options:

### M CoupeM Roadster

## 225/45ZR18(Front)

### Simplified Size: 225-45-18

Simplified size is useful for shopping and buying tires.

The original tire size for your 2008 BMW Z4 is **225/45ZR18 (Front)**. A color-coded explanation of the 2008 BMW Z4's tire size is shown below.

225 | This number indicates that your tire has a width of 225 millimeters. | ||||||

45 | This number means that your tire has an aspect ratio of 45%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 45% of the width. In this case, the sidewall height works out to be 101 millimeters. | ||||||

Z | This tire has a speed class of Z, which means it's part of an elite speed class of 149 mph or more (240 km/h). A tire's speed class is less specific than the speed rating. | ||||||

R |
| ||||||

18 | The tire size was designed to fit rims or wheels that are 18 inches in diameter. |

Trim Options:

### M CoupeM Roadster

## 255/40ZR18(Rear)

### Simplified Size: 255-40-18

Simplified size is useful for shopping and buying tires.

The original tire size for your 2008 BMW Z4 is **225/45ZR18 (Front)**. A color-coded explanation of the 2008 BMW Z4's tire size is shown below.

255 | This number indicates that your tire has a width of 255 millimeters. | ||||||

40 | This number means that your tire has an aspect ratio of 40%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 40% of the width. In this case, the sidewall height works out to be 102 millimeters. | ||||||

Z | This tire has a speed class of Z, which means it's part of an elite speed class of 149 mph or more (240 km/h). A tire's speed class is less specific than the speed rating. | ||||||

R |
| ||||||

18 | The tire size was designed to fit rims or wheels that are 18 inches in diameter. |