PSD Tire Sizes
Postmaster
Joined: Jun 2004
Posts: 2,646
Likes: 1
From: Milky Way Galaxy
jt- You're right it can be confussing. A 9" wheel isn't actually 9" wide from outside to outside. The 9" comes from measuring inside the wheel. Look closely at the "Measuring Wheel Offset" diagram on that site and you'll see what I mean. Backspace on the other hand is measured from the outside of the wheel to the back of the hub mounting surface. That's why your number's aren't adding up. I hate the use of offset as a measurement for truck wheels. It may work for people with cars, but it makes it difficult for us to figure things out. Backspacing is easier in helping to figure out if a wheel will fit.
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
Ah Ha!! And another discovery is pointed out to me. Thank you for clearing that one up. 
It seemed to me that the backspace would be the more important measurement. I also found while serching last night that the backspacing for our SD trucks should be between 4.5" and about 4.7" so the wheels I'm looking at are withing the spec.
It seemed to me that the backspace would be the more important measurement. I also found while serching last night that the backspacing for our SD trucks should be between 4.5" and about 4.7" so the wheels I'm looking at are withing the spec.
Thread
Thread Starter
Forum
Replies
Last Post
jerrymlr1
1987 - 1996 F150 & Larger F-Series Trucks
3
Jul 31, 2014 09:03 PM
Dr.Z06
1999 - 2016 Super Duty
14
Feb 14, 2005 10:17 PM
