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[Bozmo]

I have many newbie questions so I can understand more about offset, wheel size, and tires for our cars. I'm not sure if my knowledge is correct either.

1. Using the 135 wheel measurements, 7.5x18 ET49, 8.5x18 ET52, is adding a 10mm spacer equivalent to having 7.5x18 ET39, 8.5x18 ET42 wheels?

2. How do we compare 2 different width wheels and offsets of the same diameter? I'm not sure but this is how I do it.

I calculate the distance from the hub to the outside of the wheel.
A) 8.5x18 ET42: 8.5x25.4/2-52 = 55.95
B) 9x18 ET45: 9x25.4/2-45 =69.3

So wheel B sticks out 13.35mm more than wheel A. With the same diameter, 18", what's the max distance we can go from the hub without rubbing the fenders? Front and Back.

How far in from the hub to the inner wall before we rub on the inside? Front and Back.

I would think, these are the numbers we use to determine if the wheels can fit, right?


3. How do we know the max width of tires we can fit for a certain wheel?


Thanks in advance!

[MVF4Rrider]

Originally Posted by Bozmo

I have many newbie questions so I can understand more about offset, wheel size, and tires for our cars. I'm not sure if my knowledge is correct either.

1. Using the 135 wheel measurements, 7.5x18 ET49, 8.5x18 ET52, is adding a 10mm spacer equivalent to having 7.5x18 ET39, 8.5x18 ET42 wheels?

2. How do we compare 2 different width wheels and offsets of the same diameter? I'm not sure but this is how I do it.

I calculate the distance from the hub to the outside of the wheel.
A) 8.5x18 ET42: 8.5x25.4/2-52 = 55.95
B) 9x18 ET45: 9x25.4/2-45 =69.3

So wheel B sticks out 13.35mm more than wheel A. With the same diameter, 18", what's the max distance we can go from the hub without rubbing the fenders? Front and Back.

How far in from the hub to the inner wall before we rub on the inside? Front and Back.

I would think, these are the numbers we use to determine if the wheels can fit, right?


3. How do we know the max width of tires we can fit for a certain wheel?


Thanks in advance!

See if this helps...

http://www.e90post.com/forums/forumdisplay.php?f=12