Acceleratrix

I ordered some SP9000's and got the wrong profile size in the front (205/50/16). I know these will fit but here is the question: why does the S2000 come with a 55 profile in front and 50 in back?

Should I just go ahead and put these on and not worry about it or will it adversly effect performance?

VisualEchos

The effects will be minimally...BETTER. I've considered doing this on purpose, so, not to worry. You turn in will increase immidately, and it'll certainly LOOK better since the front tire LOOKS taller than the rear from the factory . If your spedo is off any at all its negligible. Good choice.

Andrew

Phantom

Acceleratrix,

205/50/16 = 24.1 inch tire radius.

205/55/16 = 24.8 inch tire radius.

The fronts and rears have different profiles (55 and 50) because the section width is different and the overall diameter stays the same (24.8 inches).

It won't do anything to your car...but I would just return them and get the right size.

Acceleratrix

Thanks for the replys guys.

I figured that it would be pretty harmless and I was hoping for positive responces. So concidering that it would be too much trouble to return, I think I'll just put them on and not worry about it.

Schatten

speedo gears/speedometer measurements are usually hooked in line with the tranny, so changing the size of the front tires would not matter. only changing the size of the rear tire size would have an effect.

E30M3

I'd be concerned with confusing the ABS...

On some cars when you vary the relative f/r tire sizes the computer is seeing enough differences in the wheel RPMs to either trigger at the wrong time or give you the yellow ABS light. This is oversimpified as there are other variables which can affect matters such as tire wear further changing diameter and things like front to rear brake force proportioning.

If you have return priveleges and like the tires otherwise I'd suggest trying them out. To see if you get the ABS light and, if not, if hard braking with ABS seems up to snuff.

Stan

Cyber Logic

Are you sure...I was always told that changing the tire size would effect the speedo...I know when we went to a bigger tire on my brothers jeep his speedo was off. Not saying you are wrong...but, I thought that bigger tires did affect it...anyone know for sure?

VisualEchos

That's what I thought Schatten, but didn't know for sure.

Andrew

Schatten

In prior experience to this car (not this car specifically), if you change the gearing in the rear end, or change the tire size, you would have to change out the speedo gear for the correct tooth count to compliment those changes.

I feel that this tire change will be negligable, if no change at all. If you are worried about carrying extra miles on the car so that isn't accurate, well... the speedo itself isn't that accurate. Its typically guaranteed up to 60 or 65mph, and after that, it has error.

I took a short road trip (6 hours one way) the other weekend, and watched how a GPS differed with the speed that my car was showing me. Even when the GPS said I was going 34 miles an hour, my speedo was between 37 and 38 miles an hour. Quite a difference. At speeds of 72 miles an hour, it was only showing 68 on the GPS. I dont' remember too many of the other numbers at upper speeds, but I can say that these are quite new tires that haven't been tracked yet. In the rear I have 245/45/16's, with full tread, so that will play some difference, which is probably what I'm seeing here. That would make perfect sense since it is consistently at 4miles above what is displayed. I'm not looking to 'correct' this, as it will soon be corrected as the tread goes down on the Yoko's.

But, from what I know - sorry that I cannot confirm this with a helms manual but can only say from what I've seen in the front suspension - the speedo isn't rated by the front tires, so if you are concerned about changing tire sizes in the front, you shouldn't be.

hope this helps.

cdelena

[QUOTE]Originally posted by Acceleratrix
[B]Thanks for the replys guys.