This is not a yes or no type question. Tires have a lot to do with it. You need to have tires available in the sizes required. Tires are far more important than the wheel. They need to match. Pick the tires you want to use and then choose the wheels. If you don't care about the tires then worrying about wheels is pointless. A set of S-03 tires for an 18" rim is going to be WAY MORE $ than for a 16" rim. Don't buy 18s and then be shocked at having to spend $1500 on tires.

 

$800 for all 4 S03's 18" from Jim at tirerack.

 

The azenis are superior to the kumhos.

 

Im riding on 18s now, but IMO - 17s are the perfect balance with looks and performance!

 

[QUOTE=revhi,Jun 9 2005, 03:15 PM] $800 for all 4 S03's 18" from Jim at tirerack.

 

Simply put it, 18" rims are a huge negative effect on the car. As soon as I put mine on I noticed a big difference in acceleration, cornering, and braking. It was pretty significant. The ride also got much harsher. I am actually going back to stock soon because I really don't like the way the car drives now.

As far as acceleration, the car has more unsprung weight. I have heard numbers like every 1 pound of unsprung weight is 8 pounds of sprung weight. Not a big difference though if your going with some light wheels. Also, the larger wheels make the car behave like it is geared higher (numerically lower) which is where I think most of the lost acceleration comes from.

 

well, sir.
that sucks. i gotta get my priorities straight over here......speed vs. style.

 

Those are the sizes I got, but I paid 800 a while back.

 

sure there are 18" out there that weigh the same as stock 16" alloys BUT you hae to remember that rotational mass is your enemy. i wouldn't go past 17".

 

Sorry to say it but that's the fault of the wheel purchaser and not the wheel.

1. The circumference of the tires must be the same as that of the stock wheels or you will change the effective gearing. A larger circumference tire will result in raise gearing, higher top speed but slower acceleration. A stock S-02 rear tire has a diameter of 24.8 inches. A BFG KD 285/30x18 has the same diameter as does the S-03 285/30x18. These will have no effect on gearing. YOU MUST USE A TIRE WITH A DIAMETER OF 24.8 INCHES EXACTLY. Not all 285/30x18 will be the same diameter. For example the Pirrelli PZero has a diameter of 25.2" an effective gearing change of +1.5% Tire rack's website has all the specs.

2. Weight is a function of the tires+wheel combined. There are 18" wheels and tires that weigh the same as stock or less. If you buy a heavier wheel and tire combo the you are adding unsprung weight. If you don't, you won't. That said an 18" tire is likely heavier than it's 16" brother because it's wider. The 18" S03 is 4 lbs heavier than it's 16" variant at 30 lbs. There are lighter tires available. The BFG gForce T/A KD is 29 lbs (and a substantially better tire too boot).

3. Cornering is a function of tires, not wheels. If your cornering ability has diminished it's because you are using the wrong tires or the wrong tires sizes. 18" wheels with the same type of tire compared to a 16" wheel and with the correct (or corrected) tires size stagger front to rear will have more cornering grip. They have a larger contact patch.

As for harsher ride, that is probably true due to the shorter side-wall. The tire is doing a lot less in terms of absorbing bumps but you can counter this with suspension changes. I've said it before elsewhere that the leg bone is connected to the hip bone. This is the biggest mistake people make in "tuning" their cars with aftermarket parts. They look only a specific part and not how that part fits with the whole. The S2000 is engineered as a system of interconnected parts. Change those parts and you change the system.

If you make good choices then you will do well but it's not going to be cheap.