i think he means if the top edge of the tire would stick out the same amount as in having the same offsetr

 

i mean if i use the same size tire would it matter that its a 9" wide vs an 8" if they both have same tire size

 

No, but the offset difference between the two will if there is any. What are your concerns? There is at least 50 people on this thread with 9 +45 225/45/17 Front. I feel like we are playing a damn Pictionary game trying to figure out your question

 

I was thinking width even though he said diameter.

If the diameter of the 8" and 9" wheels are equal to begin with(17 or 18"), the overall diameter with tires of said size will hardly be affected.

 

sorry for the confusion..example; the 17x8 +45 with a 225/45 tire is a pretty normal safe fitment. Now if i use the 17x9 +45 with the same 225/45 which is a stretch on the 9", will the top edge of the tire end up about the same distance..aka same fitment from the fender basically is it about the same fit

 

The answer is no I'm afraid, since they are the same offset, but one rim is an inch wider, that means its wider on the face, not the inner, which means its going to stick out more. It wont be a full 1" though becuase the tire is still stretched more. The rim will stick out 1" but the edge of the tire to fender only 1/2" more on outside. It can be done if you run enough negative camber. I would sort though this thread and look at all the cars with your set up in question and find out what settings/mods they did. There is plenty of them.

 

Junky the wheel doesnt stick out 1.0" wich is 25.4mm

+ 45 8.0" - "old location"
vs
+ 45 9.0"
the "new" location of the 9.0" wide wheel would be apprx 13mm or 0.51" closer to the fender

---------------------------
225 (section width) - 8.85"
45 (side wall height) - 3.98"
18
Overall dia - 25.97

225/45/18 - 8.0" flush with the wheel.
vs
225 /45/18 - 9.0" stretched on the wheel.
the side wall is now stretched 0.5" or 13mm on either side of the contact patch.

The wider wheel on the 225 tire would add .50" on both side of the wheel effecting the over all diameter by 0.25 or 6.5mm giving the side wall the stretched look.
*old overall dia of 225/45/18 on a 8.0 - 25.97
*new overall dia of 225/45/18 on a 9.0 -25.72


Conclusion!
Making a long answer short!
The edge of a 225/45/18 tire on a +45 9.0" wide rim would sit apprx 0.25" or 6.5mm closer to the fender in reference to the same tire on a +45 8.0" wide rim!

hope this helps

 

anyone have a set of 17x9 et45 with 215/40 or 225/40 dumped?

 

Your right, I was off in my base assessment of how far the 9" wheel would stick out over the 8" at the same offset, its split in half -face & back, even though the hub is at the same offset spacing of rim, the rest from there naturally falls in to place like you so eloquently broke down for us.

The tires in question are 17's so the profile dimensions would differ a bit from the 18's. The diameter fluctuations on a stretched tire would be less affected.

So are you going to quit clowning around and get a set of these or what?

 

Dooooooooo IIIIIIIIIIIIIITTTTTT!!!!!!!!