Well looks like I was wrong. Front sidewall is 40 not 30. Tires are stretched on the RCF wheel since they are stock ISF size. I plan on getting 245/40 up front and 285/35 at the back after raising it up. So much for hoping thicker sidewall would help. If I got Bilstein shocks can the springs from the KW move over to them? They should right?

 

I've seriously considered this but man 18s, unless you get something really fancy (expensive), don't look that right on this car. Maybe I should look more into it.

 

18x9.5 et 45 square look and fit perfect. Just search that size and see if you like anything. I bought Volks, which are a bit more expensive. The TC105x are gorgeous, cheaper, and lighter. PF01 is an even cheaper option, but I personally don’t think they look great. There are other options, those are just the more popular ones.

 

Thanks that helps a lot. So with my front already at 40 for sidewall will going down to 18 really mean anything to me? Is it worth it now?

 

The aspect ratio is a percentage. So 225/40 has a sidewall height that is 40% of 225. I run a 265/40, or 40% of 265. I have more sidewall than stock 225/40. If you google tire size calculator, you can play with different sizes and actually see the difference. The goal is to get more sidewall height. 265/40/18 is about the biggest sidewall height you will get in an ISF and stay close to the stock diameter (slightly taller than stock). You have the added benefit of wider tires in a heavy car, so handling will be better.

 

IMO a slightly bigger sidewall won’t help OP. I recently had an 08 I sold and had coilovers and wider wheels with thicker sidewall tires on it. When I put it back to stock 08 suspension I could feel an immediate difference. Honestly it did not feel terrible on somewhat smooth roads but it was imperfections in the road such as consistent bumps or hard bumps that reminded me why I went to coilovers in the first place. Hitting something like a railroad crossing or a pothole would make me hate the car. The stock suspension is not terribly firm, but for some reason cannot absorb those impacts well. I have also heard from numerous people that if you have aftermarket springs on 2008 suspension it is even worse. Upgraded shocks or coilovers is the way to go. Adding half an inch of sidewall would make the overall ride maybe 10 to 20% better, but likely still not be smooth enough.

 

Did you put 18s on it? What kind of sidewall? Did the 18s really not make much of a difference?

 

I had 18x9.5+38's with 255/40 and 275/35 on it last year. At that point I already had BC+swift coilovers on it that had already made it smoother. This year I went with the same wheel but in 19x9.5+45 with 255/35 and 285/30 and Michelin P4S/PSS's. Those rode better than my previous BF goodrich sport comp 2's in 18". I also went to HKS Hipermax 4 GT coilovers this year to replace the BC, they also rode better than the BC 14/10's I had and even BC+swift 16/12's I bought my new ISF with.

Ultimately what I'm saying is I've played around with 3 different coilovers, 2 sets of 19" wheels, 1 set of 18", 2 sets of OEM wheels all with various tires and the best comfort was gained from good coilovers rather than going to 18". 18" with nice sidewall will improve the ride, but updated suspension even more so, IMO.

 

So 265/40 is the widest you can go without rubbing? If so is it a square set up? How is the ride again? Also what kind of tires do you have on?

 

Awesome can't thank you enough for the info. I have kw v3s on. I've been wondering why over low speeds that road bumps and cracks hit so harsh. I just can't imagine the stock 08 suspension being worse. Wished I lived in the richer parts of Kansas. I wouldn't be complaining here. Lol.

 

I have had three different sets of wheels / tires all on stock 13 suspension, which in my opinion is sporty and smooth. I had 275/30/19 square on Kuhmo tires, which rode rough. I also had those on swift springs, stock shocks, which rode even rougher (installed by former owner). I switched to stock springs and it didn’t help much.

I went to 265/40/18 Michelin 4s in front and 285/35/18 nitto RRR drag radials rear, and it rides very well. My car currently has stock 13 wheels (for storage) with 255/35/19 DWS square. It isn’t as smooth, but not terrible.

So ironically, I had swift springs stock shocks, and hated the ride. I went OEM, and it got better, but still wasn’t great. After I started playing with tires, it got much better.

I believe 12-14 suspension is the softest setup available for an F.

In the end, I think they both matter. I do think people should buy your coils at a minimum, but honestly think they should go Ohlins Road and Track for comfort or Penske for track use. I don’t know much about your coils. It is so bizarre to me that people spend so little on suspension on such a nice car, and then hate the ride. Just buy once and cry once, and then have a nice ride. Comfort matters to me, but I’m saving for Penskes. At least with truly dual adjustable, high end shocks, you can tune them to your liking. I plan on keeping the car forever, so 3500 dollar suspension isnt unreasonable to me.

How wide you can go depends on the rim specs and how low you are. My rims are square, but running specs above for drag racing. Eventually I’ll run 265/40 square for road course. There are 265 series tires with 10 inches of tread width, which is wider than my 9.5 in wheels. Tires are listed above.

If you want smooth, go 265/40/18. If you want wide, go 275/35/18. Honestly, it’s a mute point, some 265s are wider than 275s. Just buy wide 265s and call it a day. The 40 series will absorb bumps well. If you really want to address ride properly, I suggest buying good suspension. KWs are hyped up, but I mean Penske or Ohlins, or maybe eveN touch base with LexusFanVA for feedback on his coils (I can’t comment on them).

Its a puzzle. All the pieces have to fit right, which is why LexusFan and I have both changed so many set ups. Put simply, more side wall and better suspension is the answer.

 

I just ordered B6 Bilsteins. Had to order 3 from one shop and the front right from another. All together with shipping $710.00. My car is in the body shop so I will give a review later. Really hope that the harshness goes away with the dampening.

 

Very insightful. I might get some 18s then with DWS and utilize the tire size you recommend. I do have kw v3s if you're wondering.

Very interested in this. Let me know how they go and what you're coming from. Thanks!

 

where did your order from?

 

I got the Front driver & rears from Parts Geek and the Front passenger on Amazon.

I had to look to get all 4.