Reasoning behind offset conventional wisdom

[Azrael7301]

The conventional wisdom for wheel offsets seems to be 35mm up front and 50mm in the rear. I called Forgestar and they told me that the wheels they usually sell to mustang owners are 29 front 56 rear. From what I can tell those numbers give me more positive scrub radius in the front and basically no scrub radius change from oem in the rear.

So what I'm wondering is if 35/50 is a convention because of it's handling, because of it's looks (flush vs poke ect) or because it's easy to find.

For reference I have the stock suspension and springs and make 600 rwhp (roush). I'm hoping to get a 325/30R19 in the back and I'm a bit worried it will rub at a 56mm offset. I will settle for a 315 with better scrub if that will improve handling though. (Looking at 275/35R19 in the front)

Sponsored

 

[NightmareMoon]

If you’re getting a 325 in the back with a 275 on the front, you can throw handling concerns out the window . Small changes in offset won’t fix the massive understeer from a tire combination that staggered.

offset depends. You didn’t list wheel widths, and thats needed to know if you’ll have clearance issues with a given offset.

for aftermarket front wheels offset is often about flush to fenders until the wheels get too wide, then you loose the inside clearance and the offsets may be set by that constraint.

For rear tires, theres generally plenty of space on the inside ( I just ordered some 18x12 ET57 mustang fit wheels) so offset will usually be set by the outside fender and the wheel width. I know we’ve seen 345s, but pinched on smaller wheels. (probably like 11.5s)