What is the most rubber to road I can get?

I have been searching, researching, and have found a lot of information, but wanted to be sure before I get ready to potentially purchase some new wheels for the ride now that I just paid her off

2005 330CI
Sportline Springs/Koni Yellow
Almost maxed out camber within specification
Rear fender was slightly rolled, bumper bolt slightly shaved (will probably shave more)

Here is my current setup:
OE 135s (18x8" ET46 front / 18x8.5" ET51 rear)
Stock tire sizes (225/40/18 front and 255/35/18 rear)
25mm rear spacers and 20mm front spacers (effective ET of 27 front/ET26 rear)

I very rarely ever rub, only at complete compression of the suspension, and I know I will probably need to shave the rear bumper bolts some more as they only very rarely scrape at full compression)

Here is what I want to go to:
ARC-8 (18x9.5" ET35 all around)

My question is, how much tire can I have on this setup? I really want to have as much rubber to the road, don't want to have much of a stretch either, because it will just increase my wheel gap, so please help! Based on what I have read, I can do a 255/35 all around, which on the ARC-8 wheels would be virtually square, but would that give me enough clearance all around? Could I pull off a 265/40?

Also, I have been searching for days, but haven't seen a picture exactly from the front of a coupe with this setup to confirm how much poke there will be in the front, as I really dont want to go that route either.

Please help experts! I don't plan on going with coilovers or any lower, as I drive this car hard, so I am also open to different wheel widths/offsets, but I just have to have concavity!

Thanks in advance

Nobody? Oh well lol

(Just as extra information, I don't plan on running the square setup with the spacers I already have lol)

18x9.5" ET35 wheels in a square format on an E46 are about the limit of what the car can fit. People use these wheels on their car but it is always at a compromise of using narrower tires on the wheel and a good amount of negative camber.

Almost all of the people that have used the 18x9.5" ET35 in a square fitment on their cars use a 245/35/18 because any tire that is much wider or taller is a very tough fit. A 255/35/18 could possibly fit with enough negative camber achieved through adjustable camber plates up front and fender pulling in the rear but it would not be possible though pulling the front alignment pins on your stock strut mounts alone. A 265/40/18 tire is significantly too tall and wide to fit under your fenders.

This car is using significantly stretched tires that are 245/35/18 or even smaller and you can see how far the 18x9.5" ET35 wheel pokes out from the fender:



A much better fit that is still a concave wheel would be our 18x9.5" ET43 EC-7 wheel with a 255/35/18 tire. This wheel was specifically designed with your car in mind to allow for a concave wheel but not the fender work that usually accompanies a concave wheel. The front would need a 15mm wheel spacer and negative camber achieved through adjustable camber plates.


This car has 18x8.5" ET35 and 18x9.5" ET43 EC-7's with 235/40/18 and 255/35/18 tires.