goforwand

iTrader: (132)

In looking over the many threads on this subject, there seem to be many members running 245/40/18's on an 18x9 wheel without any rubbing issues; (there are some in this thread)

https://www.evolutionm.net/forums/sh...highlight=18x9

Is the rubbing issue with 245/40/18 more a function of wheel offset or drop?

The 255/35/18 is more of a safe bet, but there seems to be less selection in this size...

stikillller

iTrader: (9)

so stick with 17's huh? damn man......all i wanted was 1 more inch, but if that means sacraficing 10whp, forget that! ill stick to 17's. Guess i will have to lower my car to get rid of that nasty gap!

naucrx

iTrader: (19)

IMO 1) only applies in some cases. If you're going from a cast 17" to a forged 18" you're probably losing mass rather than gaining it. It all depends on the wheels and tires you select.

I do agree with the rest of your post though.

To me, the most significant part about sticking with 17" is that the tires are cheaper!

AC556k

iTrader: (3)

I would agree with the above post. I just went from the stock 17's to 18" Volk LE37t's and the car actually does feel faster. I know the LE's are one of the lightest 18" wheels though. I am running 235/35/18 with Hotchkiss springs. Any wider and the rears would definitly rub.

x838nwy

The rules actually limit the diameter and width of a F1 wheels.

As for the weight issue, it depends on what wheel/tyre combination you're putting on:

I mean, if you take a look at BBS LM's and S-03's both these are recommended for Evo 8's:

LM 078: 18x8.0 +35 = 9.8kg = 21.56lbs
S-03: 235/40/18 = 26lbs
Total(18") = 47.56lbs

LM152: 17x8.0 +30 = 9.2kg = 20.24lbs
S-03: 235/45/17 = 27lbs
Total(17") = 47.24lbs

In other words, virtually the same.

If you use Eagle F1 GS-D3 then the weights are:
18": 45.56lbs
17": 46.24lbs
18's are lighter in this case.

SSR type C's are 6.93kg (15.25lbs) for 17's and 7.5kg (16.5lbs) for the 18's that's a similar sort of difference. But if you look at SSR Type C 17" + S-03 = 42.25lbs the the 17 is lighter than the LM 18" + S-03 by over 5lbs/wheel.

^I posted this on another thread, but judging by the number of posts here, it might be worth another go. It just shows that you have to look at the weights of each component to make sure that what you're putting on is lighter. Could go either way.

I agree with EvolvedMonkey. The smaller wheels tend to drive better. However, if your larger wheel is also lighter, then it will feel sharper at the expense of harsher riding.

Another thing that is good with smaller wheels is that they are more controllable near the limit - they break away more gradually since the sidewalls are more flexible. Again, this depends entirely on the tyres you're puttin on. Advans seem IMO to be very on-ff in this respect, so 18 or 19 with advans are probably not the best way to go. I have Pirelli PZero's on my STI with 18's and they are very progressive near the limit. Bridgestone RE-01R's are also very good in this respect (on 17").

In general, larger wheels tend to be for the purposes of allowing for larger brake rotors as said. For evo's only rarely do people actually intentionally end up with (appreciably) larger rolling diameter wheel/tyre combination. The gearing ratio is IMO very well spaced already, there's little need for our purposes to change it.

There are other issues also. I get the impression that the design of your wheel must influence how heat flows around your wheel assembly and the shape of the wheel must affect airflow through the rotor. A larger wheel will likely allow even stock brakes to cool better. The again, you can probably get the same effect with 17" wheels with a more 'open' design...

At the end of the day, it's probably best to go with what you like, as long as it's a decent wheel.

Soon2BEVO

iTrader: (41)

Ive always been wondering about the effect of my 18"s on my car since I know there is a loss from going to larger diameter wheel. However given I only went up 1" yet I lost about 4lbs on each wheel compared to stock, Id say it helped.

f-dub

iTrader: (5)

I = M*R^2, increasing the radius while maintaining the same mass will still result in a larger moment of inertia. A 20lb 18" wheel will have a ~12% higher moment of inertia than a 20lb 17" wheel.

x838nwy

^That's if you assume that the weights are located at the outer perimeter, which is probably mostly correct with thin spoked wheels.

As it stands, however, you could have two 17" (or both 18") wheels that weigh the same but have different rotational inertia. It's sad that wheel manufacturers don't show these in their catalogues and they're not so easy to measure.

Danny23

iTrader: (7)

my wheels are going to be 18x9 +29 not 31 i made a mistake.Can i use a 235x40 or 245x40(stock suspension) with no problems at all. i know a 255x35 will work but i dont want to go that wide. for an 06 IX any help appreciated,thanks, Danny

SP00LIN

iTrader: (6)

Danny23,

Sounds like you're going with Advan RGII or RS, eh? That's the same size rim & offset I have with RGII's and I initially went with 245/40/18. They rubbed. Then I dropped it to 35 and they fit just fine. I also ran them with Hotchkis springs and had no issues.

Now if you want to keep the size 40, then I would suggest a 235 width. The 35 rides a little stiffer, but it's not too bad. My next size is going to be 255/35/18.

If you want more info, Trinidex did a very good job on his "end all tire guide": https://www.evolutionm.net/forums/sh...hreadid=194919

Be sure to show us some pics once get them!

Sharkbite2000

iTrader: (21)

19X9 on all Fours ! and handles like a dream and the gear ratio is alot better for highway driving.

Warrtalon

iTrader: (6)

Sharkbite, you can't make comments about "handling like a dream" until you go out and race. It's highly unlikely that your 19X9s handlie like a dream, but you think they do just from daily driving on the street.

Masanari

iTrader: (1)

I'm listening...

panama-red

, than why wouldn't F1 cars have huge wheels and little rubber.[/QUOTE]






because they can use bigger brake sets...thas why....

Soon2BEVO

iTrader: (41)

Thats because the 19s will make your gear ratios taller. However, for you it doesnt matter since you have 6xx whp. For us people, it matters more!