15x8.5, 3.810 backspace - Vintage Mustang Forums
 
Thread Tools
post #1 of 4 (permalink) Old 06-27-2019, 04:24 PM Thread Starter
Junior Member
 
nenu12's Avatar
 
Join Date: Jun 2019
Location: Chico, CA
Posts: 2
15x8.5, 3.810 backspace

I purchased American Racing wheels in 15x8.5 for a mach1 70.
I took them to be able to have the option of mounting several tire widths. (from 225 to 255).
The problem is that I never tought about backspace so now I m doubting about the tire's size that I can mount on wheels without thez sub on the front Fender and rear quarter panel. After some research I saw that the tire size suggestion for a 15x8 rim and a 4.5 inch backspace is 225 / 60-15.
My first idea was to mount 235 / 60-15 in the front and 255 / 55-15 in the rear. But I just saw that rims have 3.810 inch backspace. Do you believe that these tire sizes still work ? What do you recommend?
nenu12 is offline  
Sponsored Links
Advertisement
 
post #2 of 4 (permalink) Old 06-27-2019, 10:32 PM
Junior Member
 
Join Date: Dec 2018
Posts: 19
My experience with my 70 Mustang is you need about 0 offset. That would be a backspace of 4.75 since the wheel is 1 inch wider than advertised due to the bead. I have run 295/50/15 in the rear and 265/50/15 in the front with fender rolling. I'm running 275/60 and 245/60 now. The fronts rub slightly when turning at full lock and I do run lots of negative camber.
barstowpo is offline  
post #3 of 4 (permalink) Old 06-28-2019, 04:58 AM Thread Starter
Junior Member
 
nenu12's Avatar
 
Join Date: Jun 2019
Location: Chico, CA
Posts: 2
Thanks for you answer. i'll check that
nenu12 is offline  
 
post #4 of 4 (permalink) Old 06-28-2019, 11:27 AM
Senior Member
 
Join Date: Oct 2015
Location: Anaheim
Posts: 1,189
I have both and the 15X8 with 4.500 back spacing is the hands down winner for clearance purposes. It pushes the tire in "just enough" versus the 15X8.5 with the 3.75 off set. Plus the 15X8 has the outside "look" of a 15X7 wheel . I wish they made a 15X10 that way.
Randy

'66 GT350H-3 time cover car - Car Craft July'77,Modified Mustangs and Fords Feb2011 ( w/article), Mustang Monthly June 2014. Bracket raced by me for the last 44 years. Yes it is a real one.
'68.5 R code GT fastback
'67 Ranchero 408W -427 glass hood
'78 F350 "Oleynik" car hauler
Ford Experimental parts collector
GT350HR is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Vintage Mustang Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome