2009 BMW Z4 Tire Size

There are multiple tire sizes for your 2009 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 2009 BMW Z4.

Trim Options:

sDrive30i

225/45R17 91V

Simplified Size:  225-45-17

Simplified size is useful for shopping and buying tires.

The original tire size for your 2009 BMW Z4 is 225/45R17 91V.  A color-coded explanation of the 2009 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.

RRadial
BBias Belt
DDiagonal
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.

V

This tire has a speed rating of V, which means 149 mph (240 km/h) is the maximum speed that can be sustained for 10 minutes.  A higher speed becomes dangerous.

Trim Options:

sDrive35i

225/45R17 91V(Front)

Simplified Size:  225-45-17

Simplified size is useful for shopping and buying tires.

The original tire size for your 2009 BMW Z4 is 225/45R17 91V (Front).  A color-coded explanation of the 2009 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.

RRadial
BBias Belt
DDiagonal
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.

V

This tire has a speed rating of V, which means 149 mph (240 km/h) is the maximum speed that can be sustained for 10 minutes.  A higher speed becomes dangerous.

Trim Options:

sDrive35i

255/40R17 94V(Rear)

Simplified Size:  255-40-17

Simplified size is useful for shopping and buying tires.

The original tire size for your 2009 BMW Z4 is 225/45R17 91V (Front).  A color-coded explanation of the 2009 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.

RRadial
BBias Belt
DDiagonal
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.

V

This tire has a speed rating of V, which means 149 mph (240 km/h) is the maximum speed that can be sustained for 10 minutes.  A higher speed becomes dangerous.