18's or 19's, which are better for the Z?
 

I am looking for rims, but I want look and performance, which would be better, 18 inch or 19 inch rims???

Wrong forum. Thread moved.

cant have it both, unless you find 18" rims astheticly pleasing.

I do, I dont find rubber band sidewalls to be sexy, I do not associate rim size with penis length, and thus, I do not see the appeal of large rims. all I see is a mass of metal weighing more, costing more, and risking a larger chance of damage.

but that is just me, many others like 19s, I do not DISLIKE them, I just personally dont see the appeal.

but then again, Im not totally honest, cause if I wanted performance Id be running 16s. and Im not. but I stuck with 18s. of 18 vs 19, 18s are more performance oriented.

19s are more astheticly pleasing if thats what turns you on, looks are always subjective.

Ditto on the 18s. 19s are the comparably heavier wheel/tire combo.

I hear this weight thing all the time and I'm not saying it's wrong, but most of the 19" wheels that people on this board consider weigh less than the tires that go on them, and the tires in 19" sizes (with a lower profile and wider width) are roughly the same weight (or even less) than their 18" counterparts.

What I'm saying is that the metal doesn't seem to weigh much (if at all) more than the tire, and the tires (in the same width + lower profile) weigh less.

So again, I'm not saying that this "smaller wheel = better performance" theory is wrong. But is it as noticeable as everyone makes it sound? Also, do smaller wheels only benefit acceleration/braking or do they help handling also?

well that becomes a physics problem, handling can be improved in a way, a lighter wheel combo allows the suspension to move easier, a heavy rim might bounce off a bump and hover, hurting performance, on a perfectly smooth surface, Im not sure there would be a difference in handling, but when you add a bump, its important that the tire go up and down smoothly over the obstacle.

as for ligher tire with less sidewall. this seems like it would have to be true, but then theres the whole problem, which weighs more? .5" of sidewall, or .5" of spoke? I donno. but the other problem is rotational inertia which depends on the radius from the center, in an 18" rim you put that heavy outer lip .5" closer to the center.

thats not really the biggest thing, cause you could continue, and say, oh but the .5" extra spoke is closer to center than the .5" extra sidewall...

but the larger sidewall is also good for handling, it acts as a shock absorber, flexing to absorb bumpes rather than losing traction. hence why soft walled tires are used in drag racing, you can see them wrinkle often just for that reason.

and then you have the extra sidewall offering a smoother ride, and more protection from potholes.

the difference certainly isnt night and day, of course assuming you are comparing similair rims, meaning if the rims were the same size, theyd weigh the same, easiest example would be 18" vs 19" TE37. it matters whether the asthetic appeal of the 19" rim is worth the extra cost and slight loss in performance, and loss in ride comfort.

as I kinda said, maybe not so clearly, 19" isnt a bad rim, just to me, I really dont find 19 so much cooler than 18, so even if the ONLY difference was price, I wouldnt take 19s, they arent worth anything more to me. looks are subjective, what doesnt do it for me, might do it for someone else, I like to see cars with 19s, I just dont think its personally worth my extra 300$ or whatever.

I'd like to see some thorough testing, by a magazine or something. I have a feeling a large part of the performance hit is when people change their stock tire diameter by going to 19's, and then weight after that, but it's purely speculation on my part. I have to wonder if going to a shorter gearing, ie by putting on slightly shorter tires, helps you in pure acceleration. Haven't heard much talk about that, just taller tires hurting our gearing and thus hurting acceleration.

18s still look good on the Z, but 19s to me look best. The extra price and relative reduction in ride quality would be the only drawbacks to me.

As for performance, I think the impact of extra weight would be negligible. Let's all be honest: if you had 18" TE37s and I had 19" TE37s, you're not going to run away from me in a drag or on a road course. In fact, I would think you wouldn't even be able to tell the difference. You'll notice minor imperfections in the road, but your handling or straight-line performance won't be changed in a noticeable way.

What will change your handling and performance is the tire you choose. Those CE28Ns won't help too much if you get a low-quality tire. I would spend more time seeking out a good tire than the lightest possible rim.

Just get whatever makes you happy:D

Another thing to consider when changing to any wheel is the tire you put on it. For example, the Bridgestone S-03 tires weigh from 1-3 lbs more than the Toyo Proxes T1-S (But the S-03's are wider). This is 1-3 lbs all the way out at the edge where it plays the most towards rotational mass.

Im not certain, but Im pretty sure those with 19s are keeping extremely close to stock diameter by reducing sidewall size. sadly if you change anything the overall diameter is never the SAME, mines like .5mm shorter and I stuck with 18" but since you can only get increments of 5% for sidewall widths, its impossible to get it exact. :(