The back-story... I was recently looking at 18's for my VIII. For the specific rim I was looking at, they only seem to come in 18 x 8.5 or 18 x 9.5. Inherently, I thought, gotta go with the 9.5, but then I started thinking...

For your average guy, bumping low 300 hp/tq, riding around on the street mostly, where is the benefit of the wider rims? Of course there seems to be some odd bragging rights involved with the "Damn! Can't believe you fit that!"... I don't want to down play the aesthetic value by any means, but what are the functional benefits?

- Launch traction isn't an issue in the low to mid 300s
- Wider rims = added weight
- Wider rims = more expensive tires
- Wider rims = Possible fitment issues...

So, what is the benefit? Does the handling increase greatly?

I am not attacking by any means, I am just curious for mainly street driven cars (and the occassional event), which most of us seem to have, where do you guys see the benefit?

Thoughts would be helpful...

 

In your case, I'd probably get a 9" wide rim and go with a 255.

That all fits up nicely, works well, will wear well, give good feedback and best of all ya shouldn't have any fitment issues unless you pick some crazy offsets.

17" or 18" for the street - pick your poison.

 

x2

but if those wheels you want only come in 8.5...get those and still slap the 255mm tires on them. 8.5 is fine for a 255 and 255 is all you need on an evo 8/9 for the street...hell even a race car can use 255 if setup right

 

For me, a light 17x8.5 or 18x8.5 would be perfect for the street. 245's or 255's.

People go too big for no real reason besides bragging (we're all guilty of that).

I think a light 17x8.5 with a 245 tire is way more fun then a big *** heavy 9.5 you can't use on the street.

Track cars are a different story....though starting too big impedes your learning process.

- Andrew

 

Thanks guys! Definitely appreciate the input.

PS - my thought was a 9" width originally, but the company only does 8.5 and 9.5.

 

Exactly why I am staying on 255/40 street tire on the stock BBS this season instead of something bigger.

 

In a word, no. In a lot of words, sometimes, depending.

I agree with what Andrew was saying, to a point, and with annecdotes.

On the other hand, there is also a point of diminishing returns where a wider wheel given the same tire width will maximize that tire's contact patch. Of course there's a tradeoff between tire stretch and sidewall load/flex and traction breakaway characteristics (a more stretched sidewall will have more sudden breakaway than the same tire on a narrower wheel)
Ex: STU cars all want to run 245/40 series tires because that's the class standard/limit. Nats have been won on a stock MR BBS with a 245, but the most consistent national winning STU car runs 245/40 on a 9.5 (take that anti-stretch people). I tried that same setup with very high spring rates and valving to match+ very stiff rear bar. Not surprisingly, it wasn't long until I wanted to try 9" instead for more progressive breakaway. My fast friend in STU who had the 245's on a 8.5 wanted to try 9 and 9.5." Try to squeeze a 245 on an 7.5" rim is possible, but handling starts to suffer and get "squirmy" because too much of the cars energy is transferred into sidewall flex as the tire "rolls" around on the narrow rim (see A-Stock cars)
IMO for that use the 9" would have been a good balance between maximizing the tire's contact patch, sidewall load bearing ability/flex/breakaway characteristics, weight, and handling.

Now if we were talking about drag racing, you would want the lightest (often narrower) wheel possible and you want really soft sidewalls tun be able to load them up and run low pressure, so a wide tire on a narrow rim is ideal.

YMMV.

As I always tell people: establish what your use/goals are, see what the people getting the best results in your intended use are using, and do that. Modify to your preference/results from there.

 

Wider wheels are better to an extent. Wider wheels let you run wider tires, but if you cant warm up the wider tread your handling will suffer. Im running 18x9 with 255 star specs, the wheels fit with no rubbing and its plenty enough tread imo.