Backspace & Offset
Thread Starter
Member
Joined: May 2021
Posts: 154
Likes: 29
From: The Great State of Texas
GL450
Backspace & Offset
Other than the Dealer, where can I get the wheel size on my car?
Backspace, Offset, wheel width.
I know they are 19" since it has 275/55/19 size tires, thanks!
Chad
Backspace, Offset, wheel width.
I know they are 19" since it has 275/55/19 size tires, thanks!
Chad
Thread Starter
Member
Joined: May 2021
Posts: 154
Likes: 29
From: The Great State of Texas
GL450
Looking for a set of wheels for my Wife's car, found some on here; https://mbworld.org/forums/market/813990
These are Vossen Wheels 19x8.5 +45 Front and 19x10 +55 Back and I like them but I was hoping for 20" or better. But for the price he's asking its worth considering the 19's since that size is on the car already. I'm not sure of the backspace, offset or size of the wheels that came on the car from the factory other than they are 19's because of the tire size, 275/55/19.
Chad
These are Vossen Wheels 19x8.5 +45 Front and 19x10 +55 Back and I like them but I was hoping for 20" or better. But for the price he's asking its worth considering the 19's since that size is on the car already. I'm not sure of the backspace, offset or size of the wheels that came on the car from the factory other than they are 19's because of the tire size, 275/55/19.
Chad
Super Member
Joined: Nov 2019
Posts: 648
Likes: 144
From: Yeast Coast, Canada
GL550 X164
Offset is stamped on the wheels. Look inside one of the wheels on the spokes for ET followed by + and two digits. Backspace can be calculated if you know the wheel width and offset.
(wheel width +1) / 2 + (offset / 25.4) = backspace
Since wheel width is measured bead to bead, adding 1 inch to the wheel width accommodates for inner to outer surface measurement. Offset is measured in mm, dividing by 25.4 will convert it to inches. The formula will render the backspace in inches.
Alternatively, backspace could be measured using a ruler or another straight object, like a level, and tape. Lay the wheel flat, face down (no tire mounted on the wheel). Place a ruler across the wheel and measure the distance from hub to the ruler's lower edge.
(wheel width +1) / 2 + (offset / 25.4) = backspace
Since wheel width is measured bead to bead, adding 1 inch to the wheel width accommodates for inner to outer surface measurement. Offset is measured in mm, dividing by 25.4 will convert it to inches. The formula will render the backspace in inches.
Alternatively, backspace could be measured using a ruler or another straight object, like a level, and tape. Lay the wheel flat, face down (no tire mounted on the wheel). Place a ruler across the wheel and measure the distance from hub to the ruler's lower edge.
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E55, GLS450, GL63, GLE350
Tirerack is a good source for finding the right type fitment for your car. There are also online calculators available to you for wheel sizing. Wheel Offset Calculator | Find Your Offset | Custom Offsets (customwheeloffset.com)
