JSWhaler

I'm glad I keep my spare in my car. A few weeks ago I had a blow out, the tires bead actually broke. Fix a flat would do nothing for this kind of problem.
Just stick with your OEM spare and you should be fine. As others already stated do NOT put the spare on the reear.

SpitfireS

Allright..
The way I understand it, is that the OP wants to have a full sized wheel in the trunk as a spare, not the OEM "skinny" wheel/tire.
That is not a bad decision, it will cost you trunk space, but if you have the proper size wheel & tire in the trunk you will be able to drive "relatively normal" to and/or back from work in case of a flat.
To do this absolutely perfect one would have to keep 2 spares in the trunk because the S2000 has a staggered wheel/tire setup.
(that is not an option because it will not fit )
Another thing to remember is that the front and rear hub sizes aren't the same.
Front = 70mm.
Rear = 64mm.
So your full size spare would need to have a centering hole of at least 70mm.
Needless to say you also need the proper lug nuts with the spare wheel (there is difference between them too, OEM's have a spherical (ball) seat and most aftermarket wheels (IIRC) use tapered (conical) seats.

Trigun Posted: Nov 15 2006, 08:41 PM
Trigun Posted on Nov 16 2006, 03:08 AM
Now I am assuming those are the tires you have on the spare's mentioned above.
Those 225/40/18 tires have a circumference of (approximatley) 2,0018 meters.
The OEM 245/40/17 rear tires are (approximatley) 1,9723 meters.
That (the 2,0018) is about 1,5% more then the OEM tires (and IMO it is getting a bit tricky to use that difference at the rear because it may damage your diff) but you are not using the OEM wheels & tires anymore....
FYI.. my compact spare, a T125/70 D 16 96M has a circumference of (approximatley) 1.827 meters, that is one of the reasons you can not use it (because it won't fit => the hub size ) at the rear, too much difference in circumference.
The main reason is that it's just too skinny to handle the driving force.

So now "we" need to know what tires you have on your S2000 at this moment.
Front and back please

Trigun

Thanks for the informative reply.

My current setup is.

18" Volk TE37's

18x7.5 with +48 offset in the front (225/40/18 tires)
18x8.5 with +50 offset in the rears (245/40/18 tires)

Car is not currently lowered.

SpitfireS

First I have to correct myself.
(before I get corrected )
The OEM compact spare will fit at the rear (I was experiencing a brain fart thinking that the centering hole would not allow it....), it has a centering hole of 70 mm to make it fit at the front so it would fit at the rear too.
Not that you ever should do that ....

Anyway..
Your current tires have a (huge) difference in circumference.
Front 225/40/18 give 2,0018 meters.
Rear 245/40/18 give 2,0521 meters.
That is a -2,45% difference (taking the rears as reference)

Your spare set also has the 225/40/18 tire so I would not recommend using them at the rear because it may (probably will) damage your Torsen diff.
The "OEM option" of using the front at the rear and the spare at the front would not work for you either for the same reasons (they are the same tires).

Your old (and probably sold) OEM wheels and tires do not have such a difference in circumference.
For a reason.

OEM Front 215/45/17 give 1,9644 meters.
OEM Rear 245/40/17 give 1,9723 meters.
That is a -0,4 % difference (taking the rears as reference)
With such a low difference it is ok to "mix" wheels on the rear.

You should (IMO) use a tire size on your full size spare wheel that comes closer (as close as the OEM diference) to the rears you are using now.
Another 245/40/18 tire? (might be to wide to use at the front)

If you at one point have to use it at the front you may get ABS problems because of the difference in circumference.

The 18" will limit your choice in tires.

Or use the fix-a-flat stuff, I donno.

I'm very, very happy with my OEM wheels and tires