I would like to know if anyone has successfully mounted the following Kumho SPTs on their AP1 wheels:

Front: 225/50R16
Rear: 245/50R16

For those who are curious, here is a comparison of specs between the OEM wheels and the SPTs

Make * Tire Size * Rim Range * Overall Dia * Section Width * Weight(lbs.)

SPTs * 225/50R16 * 6.0-8.0 * 24.9 * 9.2 * 23.5
SPTs * 245/50R16 * 7.0-8.5 * 25.7 * 10 * 27.5
S-02 * 205/55R16 * 5.5-7.5 * 25.0 * 8.1 * 22
S-02 * 225/50R16 * 6.0-8.0 * 24.8 * 9.2 * 25

AP1 Wheels
Front 16" x 6.5" Aluminum Alloy
Rear 16" x 7.5" Aluminum Alloy

Thanks!
Rory

 

[QUOTE=armodis,Sep 20 2007, 01:40 PM]

 

Thanks for responding with some info. I've seen the ABS issue mentioned in the forums... will you please explain why the height causes a problem with the ABS? Also, this graph is pretty confusing, sorry about that. The diameters are:

Make * Tire Size * Rim Range * Overall Dia * Section Width * Weight(lbs.)
SPTs * 225/50R16 * 6.0-8.0 * 24.9 * 9.2 * 23.5
SPTs * 245/50R16 * 7.0-8.5 * 25.7 * 10 * 27.5
S-02 * 205/55R16 * 5.5-7.5 * 25.0 * 8.1 * 22
S-02 * 225/50R16 * 6.0-8.0 * 24.8 * 9.2 * 25

so that puts it at 3.5%... is that still to much for the ABS? I'm fine with rolling my fenders if that's needed for another .5%

Thanks again!
Rory

 

ABS doesn't care what the front/rear diams are. If you're running on a 2006 or later, then you would have to keep them the same ratio as stock due to the Vehicle Stability Assist system but ABS by its very nature CANNOT be sensitive to tire diam differences between front and rear. Whoever tells you otherwise is not speaking from first-hand knowledge.

As for speedo, yeah that will be off but I'm sure he knows that that and besides, how does any difference between front/rear (>3% or otherwise) have anything to do with this? This is only an issue if the rear tires are different in diam than the stock tires and has absolutely nothing to do with the front tires. Additionally, everybody and their brother out there running way-large tire packages in the rear have this problem so if you're willing to deal with the speedo being off, who cares? The car doesn't.

And lastly, how does a >3% difference in diam between front and rear affect rubbing or did you mean >3% difference from stock tire size?



Back to the question, I've not see that size combo on an S2k before but it appears it may work though the front will likely be a tight fit with the 50-series in that width.

So, the question remains...

Has anyone ran a 225/50-16 on the front with the stock 16" wheels?

Has anyone ran a 245/50-16 on the rear with the stock 16" wheels?

I'm curious about this myself as I had a chance to drive a friends M3 with SPTs on it and they were amazing for such a cheap/long lasting tire. But, as the poster has found out, they don't make them in the most popular S2k-friendly 16" sizes. But man what an awesome daily-driven tire... if they will fit !

-=dave

 

I am not speaking from logic? You think I just made up the 3% difference for the fun of it? You should know that that is not my estimate, but an estimate that is the sum of much experience of many experts. Do a google search and see for yourself. The 3% rule is a guideline by which enthusiasts can play around with OD of wheels and tires without causing too much detriment to their vehicles.
Before you call people out for not knowing what they are talking about, perhaps you should ask for some qualifications... or better yet present your own. I know, from working in a wheel and tire shop for nearly three years, that vehicle systems like ABS are more sensitive than most people think. It may not seem like a huge difference when you are playing with tire sizes and changes in OD, but your vehicle can sense it.
Why would it be so important to try to stick as close to the original OD when plus sizing or zero sizing tires and wheels? If you just throw on a package that has an increase in 2 inches over the original package do you think everything will be fine?
As for the difference in speedo- duh... the rolling diameter of the tire will change if you change the size too much. Even if the change is just in the rear, a change will still be there.
The issue with rubbing can happen even when you have original wheels on your car. When you start playing with profile and tread section numbers, you can end up with a car that makes your car sit higher or lower than it was originally intended. This means that the car has an increased chance of making some kind of unwanted contact with the tires.
To make an example- I once had a good friend with a 2005 S2000 come to replace his rear tires. He had wheels on the car that were similar to stock specs with a 245-40-17. He wanted to go to 255-40-17. He did, and ended up with rubbing problems. Even though the wheel did not change, the small change it width and height of the tire ended up causing problems. The 3% thing does not really come into play here; it is a bit less predictable.
As for "who cares"? The original poster does. Sorry that everyone here doesn't have such a cavalier attitude towards their cars as others, but the OP asked a question that was designed to get specific, qualified, information. All you have managed to do is refute what I said to no beneficial end. I would suggest that you would relax and realize that some of us have been at this longer than you, Mr 2 day veteran.
If you want to get a second opinion, ask another professional- Jim @ the tirerack. He is always in here, and I am sure he would be glad to give you his opinion.

 

i claimed no such thing but let me backtrack...

i think i may have had a bit too much caffeine so sorry if my response seemed too directed at you personally. it just gets to me when people ask specific questions on most automotive forums (in my 2 days of experience with them ; ) and get canned responses quoting general guidelines that, if the poster had done their homework, would already know. i try to give people the benefit of the doubt and expect they did their general homework before asking specific questions such as "has anyone tried this wheel/tire combo" and try to give them useful answers or general recommendations based on my own experience. i will not tell someone anything i don't know for a fact. of course, we are limited by the medium so certainly there are always miscommunications that wouldn't exist in speaking directly to each other but that's generally how i see it.

that said, i read the posters question more as "i realize this package isn't ideal but has anyone tried it or can anyone state that it will absolutely not work at all"? This may be due to the fact that I am aware of the generally excellent experiences people have been having with the SPTs as well as the limited SPT 16" sizes available and figured that's why he was considering the less-than-ideal 245/50 rear fitment... because he had done his homework, found an excellent "daily driver" tire and was willing to compromise on sizes to get it to work. i did not think he was too concerned over the speedo being off since most knowledgeable people know that a change in tire size affects speedo accuracy. You claimed that he said he was concerned over the speedo accuracy but I saw no such statement.

As for my statements, I also must apologize for not being more specific since, now after reading it, i realize i made some claims that were written as absolutes which in fact should have been qualified further. i was merely being lazy, which contributed grossly to the misunderstanding.


The bottom line is that I am not attacking you. However, I still take issue with some of your claims. Since you have valuable direct experience I will ask these specific questions:

Q1) You have witnessed CEL errors on a non-VSA S2000 resulting from front and rear tire diameters being approximately 7.3% or smaller difference between the front and rear diameters?

(typically systems are designed to withstand ~10% constant-velocity difference before triggering a fault condition, certain Hyndai models being the only exception I have personally heard of. If the same is true of the ABS system on the Honda S2000 and it is hypersensetive to constant-velocity differentials between front and rear axles, then, again, please accept my apology.)

Q2) Is it absolutely not possible to mount those tires sizes on their respective ends and have them be rub-free?

(this question can only be answered by someone intimately familiar with the components in question and even then, the question is likely impossible to answer if the sizes may be "close" to fitting. For example, I can say with 100% certainty that a 245/50-16 cannot fit in the front. With my direct knowledge I cannot say if the 225/50-16 absolutely will not fit so someone with more direct knowledge such as yourself may be able to better answer.)

Q3) Have you or anyone else you know attempted to mount tires of either of the sizes in question on the early S2000? If so, what was your/their experience?

Thanks and sorry again for getting off on the wrong foot

-=dave

 

To clarify, I'm not concerned about the speedo issue but I appreciate you providing all of the information you have. I am pretty interested in knowing the mechanical or electrical cause of an issue with ABS because it sounds interesting! But mostly I'd just like to know if anyone has been able to fit those sizes because I'm willing to play around and see what it feels like.