Calculating Offset

i am not the most knowledgeable in this topic and since my car is in storage i cant physically measure

i am just curious how i would go about calculating what offsets i am going to need to achieve the fitment i want

i know my stock wheels are

17x8
6.295" backspacing
45mm offset
all around


the 20s i had on my 05 were

20x8.5
30mm
20x10.5
45mm

if i am wanting to go

20x9 fronts
20x11 -11.5 rears

and also having them out a little more flush(my 20s were not quite flush)

am i going to stick with my same offsets? does someone have a calculation chart, etc?

Thanks!
Dustin

240sxy wrote:

http://www.1010tires.com/WheelOffsetCalculator.asp

it looks like i am going to need to go to the farm and measure the spacing, as i am not sure how much room i have to the strut.

this still doesn't make a bunch of sense to me though haha

Well you know your stock backspacing is 6.3" so as long as you keep at least that much you'll be ok on the inside. (I assume you can get away with a lot less backspacing on the rears?) But if you want to know exactly how little you can actually get away with, then just post up on a mustang board. Somebody will know.

http://www.willtheyfit.com/

Is nice for a visual idea of how much more in or out they are going to be.
(The little strut graphic doesn't mean shit, just there for something to look at)

What are you putting on the rears? 295/30-20?

im not really sure what tires i am going to do in the rear

flush on a 10inch rim is a 295 maybe a 305 so on a 11 or 11.5 i think a 265 to 275 would give me a nice little stretch.

and yes, i am going to stretch tires on a mustang. haha.

youre going to have to buy the wheels first and put the on the car to see what size tire youre going to need.

this is 265/35/*18* on 11.5
which is a super over kill stretch unless your poking that much.

unless you look at other mustang owners who have more "flush" wheels and do the calculations off their sizing, you cant really do anything without having your car. youre going to end up guesstimating and fucking it up.

http://rimtuck.com/setup/view/1222

this is pretty much the fitment i am looking for.

but i want 20x11 or 11.5 as opposed to 18x10

it helps to use a site like tirerack.com becasue they will let you know what the tires actually measure, becasue more often than not, two 285/30R20s, from two different manufactures will measure two different sizes.

that s14 is the tits

Jhall wrote:

that s14 is the tits

What were we talking about again?