When you order the 18" wheels from Acura, their recommended tires are Yokohama Advan Sport (225/40R18). Don't forget you need to order TPMS sensors for each wheel unless you are transferring your stock 17" ones.</B>
I've done a little bit of research on this (years ago and also a couple weeks ago) regarding this same exact issue.
I previously owned some 18x7.5's with 225/40 tires on a different car. Tires looked nice and square with the wheels.
All of these opinions are on 18x8 wheels, both stock and aftermarket.
On this car, Honda is using 235/45/18 on their 18x8 wheels. Me personally, I think the tire looks too big/bubbly in some views, while in others it looks just fine. This tire is somewhat not as common to find either, so expect to pay more money for less choices.
245/40/18 will look like a nice large meaty tire, and IMO you should only get this if you want that look.
225/45/18 will look slightly less wider on the wheel, but will look good height wise. This is also a common tire size, that will give you lots of options and prices.
There's a few other things to note: tire sizes go by what the inside width is, while the tread width can be a different number. When you look up detailed tire specifications, they should tell you what the "tread width" is. If you want a wider tire, definitely pay attention to these tread width numbers, not just the 245/225 thing.
I personally will be going with a 225/45/18. Just need to do your research on tread width, price, and type/options. For example, here's a picture of an Audi TT that has the exact wheels I want with the tire size I want. This look/width/tire height is exactly what I want.
That said, another issue that you're going to deal with is the rims you have chosen. You've chosen rims that have a medium lip, and the style itself will also make the wheels look smaller than they really are. Your wheels are going to look like 16-17's rather than 18's. If you like this style (racecar ish, old bmw style), then great. If you want something that looks like big aftermarket wheels, you will be VERY disappointed. Wheels with lips will always make them look smaller. Notice the Audi I posted, looks more like 19's than 18's, and Derwood's 19's look more like 20's.
Good luck! PM me with any more comments or questions
Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for Acurazine.com content, comments, or advertising. Acurazine.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse Acurazine.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.