I don't know the offset your running on the front so I'll limit my comments to what I know. I ran a 235/40/18 on the stock rim but the clearance to the suspension bolt was a credit card width. It was ok on the street but I ran a 5mm spacer at the track. With a 32 offset a 245/35/18 fits perfectly. If your lowered more than 1/2 inch in the front even the stock tire will rub a little here and there under the right circumstances. I'm currently running a 255/35/18 on the front and it would hit the fender lip on huge bumps or under panic braking. I rolled the front fenders a bit and now it's fine. Thats on a 18 by 9" rim with a 32 mm offset. You can extrapolate from my numbers with my 1/2" drop in front. If your lowered more than me the inner fender liner will be rubbed when turning sharply. The fender liner can be coaxed to bow out of the way, I've done it, but it didn't stay bowed out of the way. With conviction you could get it to stay bowed IMO. You have the tire, mount it and make the adjustments necessary. I polished the inner bolt but I don't think it was necessary. What can I say, I'm a worry wart like you.

Les