How much do you think we can change the wheel diameter
when changing to aftermarket setups??

I'm shopping for a new setup on my sedan and am trying to
get a good staggered rubber setup.

I'm concerned about deviating too much from stock DIA,
which is 26.4" (sedan). I want to go smaller but is there a limit???

Here are a 3 examples: (based on 18" rims)
Tire DIA varries with each mfg. so I'm using Pilot sport data
because they have a large size selection.

OPTION 1 (aprox -0.5" deviation)
fr - 225/45 DIA= 25.8
rr - 255/40 DIA= 25.9

OPTION 2 (aprox -1.0" deviation)
fr - 235/40 DIA= 25.4
rr - 265/35 DIA= 25.3

OPTION 3 (aprox -0.6" deviation)
fr - 245/40 DIA= 25.8
rr - 275/35 DIA= 25.7

I'm lowered on Eibachs & will be running 8"fr & 9"rr rims
I think that option 2 would be my prefered setup, allowing some space for camber adjustment.
I know several are running 275s at the back, but I think that with proper camber, they might be tight (depending on offset of course)

So.....
What it comes down to;
Do you think the Option 2 setup (dia) is going to be to small???

Any help appreciated.