dshea

You really can't find anything other than the Michelin MXV4 S8, the Goodyear RS-A and the Bridgestone Blizzak WS-50 for the OEM 235/55R18 size. The only other size that comes close to the overall diameter of these tires is the Pirelli PZero System Asimmetrico 255/50R18. So I guess the question is: Will 255/50R18 fit without sticking out and without rubbing? If so, what wheel or rim width (probably 8") and what offset (I'm guessing +35 or less - maybe +30 or +32)? Has anyone tried it with a tuner or care to speculate?

JRB

On my winter set-up I am running 18 x 8 inch wheels with the (stock size) Blizzak WS-50 and they fit fine with no rubbing. The offset on the wheel, which is a Mille Miglia Spider II, is ET40. Since this is for winter use only I was not interested in going any wider, so I cannot help you there. You might want to call TireRack and see what they have to say.

JohnsRX

i know all the specs, but since u are only putting on 18s, im not telling.
Talk to me when u want 19s or atleast 20s.

dshea

JRB:

Thanks for the info. Brandon of The Tire Rack on the Tire and Wheels forum has already said he didn't know whether a 255/50R18 will fit
Your setup pushes the rims about 0.2 inches in, but the extra width compensates and gives you a total 0.6 inch extra track width. But it also moves the inside tire surface 0.7 inches closer the the strut. This worries me a little because I have the performance package with the air suspension. Is that what you have? It'll give me some idea how much I can go before it rubs against the strut.

JohnsRX:

The rim diameter has nothing to do with it. But I guess you know that and is only being facetious.
But seriously, your signature has the specs for a RX300, not a RX330. I'm not sure how different the wheel well dimensions are between these two generations, but I'm sure they're different.

JohnsRX

haha, im teasing, because i want u to get DUBS!!! I have studied the 330's aftermarket wheel specs on both 19s&20s, as a matter of fact i just bought a magazine about it, because im sure im gonna step into a 330 or FX after this one. And since i always shop for rims before i buy the car, i can tell u that the 330's offset is even more extreme than the 300. I dont like to use spacers, so i seen rims with an offset of 18! Of course this means u gonna have a nice rim with a deep lip which i love, but as u already know not many rims if any on sale in the U.S has that kind of offset. And about your max 18" tire size, im not telling.
Ur car deserves 20s!!

dshea

I'm trying to keep the overall unsprung weight at about equal or less than OEM. 255's are going to be heavier than 235's. I'm hoping to offset the extra weight by staying with light weight 18s. If I can keep the overall weight the same or less, I'll have no problems going with larger diameter rims.

Anyone know how much 2004 OEM 18 inch wheels weigh?

JRB

Yes, we do have the performance package also. Looking at it in the garage just now it looks like there is about one inch of clearance between the top of the tire and the strut.

dshea

I lowered the full size spare (Graphite 18" rims with Goodyear Eagle RS-A 235/55R18) and weighed it at 55 lbs Assuming the tire is 25 lbs, the rims weight a whopping 30 lbs! Just by changing to aftermarket rims that weigh 25 to 19 lbs each, we can save a total of 20 to 44 pounds. Using the 10 to 1 weight to horsepower ratio rule of thumb, that's a realized gain of 2 to 4.4 horsepower from weight savings alone (Not to mention the added benefit of less unsprung weight in handling and improved fuel economy). If I remove the 55 lbs spare, it'll net me another 5.5 horsepower for a total gain of up to 9.9 horsepower. That should raise total (realized) horsepower from 235 to 245. But then, it's a SUV, not a track car. I guess my point is that I'd rather not add more weight to the vehicle, especially unsprung weight.

JRB:

That's good to know!

JohnsRX

i wasnt gonna respond when u posted ur previous weight concerning thread, but u are killing me here with this one. I thought i was on rennlist talking about our turbos, i double checked the headers and realize i wasnt in the wrong site so there must be something wrong with u. Hehehe.
Im impressed with ur thinking, but i use ur concerns on my other cars which always have a lot more than 300 horses and weighs less than 2700ibds.

dshea

LOL The RX is not my usuall ride. It's my wife's. Thinking about weight savings is a habit I picked up from owning 3 consecutive sport cars ('92 VR4, '00 S2000, and '02 S2000).

JohnsRX

Ok, ur forgiven. I know a little something about the S2k too, my best friend's ride: