Russ

1. What is the OEM stagger in tread width between front and rear tires on the 00-03 S2000?
1.6-inches. Spec-wise, it's actually 1.4 but the measured wheel width of the 225/50/16
SO-2 was done on a 7-inch wheel and since Honda uses a 7.5-inch wheel, tread width
increases by .2 inches. The rear SO-2's tread width on the Honda rear wheel is 8.7-inches.
2. What other 225 tires offer the same "245" width as the rear SO-2 Bridgestones?
Well, if you can believe tire specs as broken down by the company, there are indeed, two manufacturers. The Sumitomo HTR Z and the Dunlop SP Sport 8000 I wouldn't go so far as to believe this without side by side proof but if you want to go strictly on manufacturers claims as printed by Tire Rack, here is a breakdown of some 225/50/16 tread widths. Note the widths will be calculated using Honda's 7.5-inch rear wheel. I've also added (if available) the corresponding 205/55/16
tread contact #'s using Honda's 6.5-inch front wheel.

Bridgestone SO-2 8.7-inches, 7.1-inches (front)
Bridgestone SO-3 8.5-inches, 7.6-inches (front)
Bridgestone RE050 8.3-inches (runflat)
Bridgestone SO-1 8.1-inches, 7.2-inches (front)
Bridgestone RE750 7.4-inches, 6.6-inches (front)
Bridgestone RE010 8.4-inches

Yokohama AVS Sport 8.1-inches, 7.1-inches (front)
Yokohama ES100 8.5-inches, 7.5-inches (front)
Yokohama A022H1 8.1-inches

Sumitomo HTR Z 8.8-inches, 7.4-inches (front)

Kumho MX (no results given)
Kumho Ecsta 712 8.2-inches, 7.2-inches (front)

Goodyear Eagle F1 GS-D3 7.5-inches, 6.7-inches (front)
Goodyear Eagle HP Ultra Plus 8.5-inches, 7.7-inches (front)

Firestone Firehawk SZ50 EP 7.2-inches, 6.5-inches (front)

Dunlop SP Sport 9000 8.3-inches, 7.2-inches (front)
Dunlop SP Sport 8000 9.1-inches, 7.6-inches (front)

BFGoodrich g-Force T/A KDW 7.4-inches, 6.6-inches (front)

Dunlop SP Sport FM901 8.4-inches, 7.2-inches (front)

Falken GRB FK-451 8.5-inches, 7.6-inches (front)

Please note Toyo, Pirelli, Michelin, etc do not provide actual measured tread
width statistics. Do not use section width as a guide to replace the missing
information as it will not be accurate. Section width, in laymen's terms, is the width of the tire (if you measured it from the top) while tread width is the actual width
of the tire that comes into contact with the surface of the road. Some sidewalls like the SO-2 are very vertical and thus this explains why their tread width corresponds
to tires sized more akin to a 245 however not all 245/45/16's are correct
replacement tires for the SO-2's either. For example, a BFGoodrich g-Force T/A KDW 245/45/16 has a tread width (when mounted on the stock rear wheel) of only 7.7-inches, nowhere near the stock 225/50/16 SO-2.

More questions:

3. Why is offset so important when selecting aftermarket wheels for the S2000?
Due to the relative low number of moderately priced aftermarket wheels for the S2000, many owners find themselves looking at $250/wheel brands (MSRP) with
offsets between 40-48. In all but a few cases, these wheels will not come in staggered sizes (17x8, 17x7.5, etc), rather 17x7, 18x7.5, etc. When you move from
the standard S2000 offsets (55/65) for the 00-03 models, nine times out of 10 you're moving to a wheel with a lower offset. This means the wheel edge will move outboard. The distance will be determined by a combination of the wheel width and offset. This link should be bookmarked for all. It will help you a ton.
http://gs.tolan-hoechst.com/tirecalc.htm
Now, when you choose a wheel with a 40-48 offset, because you are moving
the wheel edge further outboard, you will also be placing the edge of the mounted
tire equally as outboard. Because the stock tire has the width of a 245mm tire, you
can usually mount a replacement 225/50/16 tire on the car with any wheel in that
offset range and have no problems rubbing. The reason being the distance your new
wheel goes outboard is offset by the fact that you're using a legit 225mm tire. You
can lower your car and still be in a situation where you shouldn't rub (depending of course, on the amount of drop). When this car was a year or two into its inception, the general opinion was anything less than OEM was wrong. It isn't WRONG, it's different. You have to realize that going with an aftermarket 205/225 set-up will reduce (in most cases as noted above with the #'s) your stagger. Expect it to go
from 1.6-inches to as little as .6 or .7 inches. Is this bad? Not necessarilly. It depends a great deal on your driving skill and driving style. If you drive your car
to its absolute limits on public roads, I would recommend stock stagger if at all
possible. There is no sense bringing a knife to a gun fight. However, if you drive
at moderately quick levels but keep things relatively sane, the drop in stagger will
only become apparent when your combination of braking, turning, speed all reach
a level that results in loss of traction. IOW, you're not going to notice the 1-inch
of stagger loss going to the video store unless you go there with the vision that
between your home and the video store is Suzuka or Imola. If your priorities are
long wear and wet weather capability, extreme performance and handling will not
be your main goal and thus, expect less stagger but because you're going with
a narrower tire in the rear, wet weather traction will, in of itself, be improved. A
narrow tire is much better in the rain than a wider tire of the same make/brand.
One other item to note. In cases where lower offset wheels are being used, your tire track will increase. I prefer to recommend (to those who ask) to keep things under
1-inch outboard. Anything more than that would put too much stress on the
suspension as a result of the increased tire track. If you keep things under 1-inch
outboard, the increased tire track WILL compensate to some degree, the reduced
tire width you are using (if you are going with an aftermarket 225). You can also,
if you're really judicious, adjust your alignment and even place a firmer front sway bar to bring things back to stock levels of handling

4. Can I use same sized tires on all four corners?
You can and some folks do but without sway bar adjustments and a real spot-on
alignment, if you're going with this set-up, be honest with your own driving style
and proceed accordingly. If your S2000 is a daily driver seldom driven aggressively,
you can run same sized tires (providing your wheels are sized correctly) and you
probably would be none the worse. Not every owner of this car is a Juan Pablo wannabe, let's face it. Having said that however, you are creating a car that is LESS
than what it WAS. If you're fine with that, so be it. To me, if tire wear is that much of a concern, just get a more compliant street tire (Proxes T1-S, etc) that wears longer than the SO-2's. I know a few owners who do run same size tires and remark that they feel the car is a more neutral automobile at the limits. Once again, the leading parameter in deciding whether or not to do this would be your own driving style. There aren't many doing it and those who do (that I know) are skilled enough
to understand the nuances of doing so.

5. Rotational weight? What is that?
Simple. Weight that rotates (tires/wheels/flywheels, etc). To the best of my experience (and research, in addition to personal observation using a Tazzo unit), unsprung weight from tires/wheels is equal to 2-2.5x actual weight. For example,
a 12-lb wheel on all four corners (when compared to 00-03 stock wheel weights) would result in a weight savings akin to dropping 62-lbs from your car. FWIW,
the lightest performance tire (like-sized) available is the Toyo Proxes T1-S. It can
often weigh as much as 4-lbs less than another brand tire of the exact same size.
I'll use myself as an example. With my last combination (Toyo, Rota Slipstream),
I weighed one of my rear wheels/tires and it was 31-lbs. I believe the stock rear
tire/wheel weighs 42.8-lbs. I had lost 59-lbs of weight just from the two rear
tire/wheels alone when compared to stock. If you want to extrapolate this into
real world #'s, I have (through more than 200 Tazzo runs over the years) come
up with this formula which seems to be pretty darn accurate (least for me).
For every 10-lbs of weight saved, expect a .02 drop in your 1/4-mile time (all
other environmental and conditions same) OR
100-lbs of weight saved is akin to a 10hp increase in power. With any lightweight
sportscar, losing weight is simply FREE horsepower or more accurately, a way to
improve your power to weight ratio. Of course you don't actually CREATE horsepower.

I hope those who made it through this entire thread have been helped in some
small way. It seems I read the same questions over and over again despite the
NOTE at the top of this forum. This thread was written not to replace that
one, rather to compliment it. I hope it will.

soundzero

Can we make this sticky?

PJK3

Russ -- would it be possible for you to include a list of comparisons for the equivalent 245/45/16's on the 7.5" rim to the 205/55/16 on the 6.5" rim for the same manufacturers/models to assist us in matching the OEM stagger?

thanks -- great post.

subscribing.

personal keyword: evenflo

mhaines

Am I reading this correctly...?

If I get es100 tires, do I just buy the same size as the original SO2 tires? The difference seems minimal.

I am looking for new tires, but I want more treadlife out of the new tires. Should I expect 10k to 15k out of anytire I place on the car?

Thanks