NYS2K

I don

TubeDriver

Even tread wear on my 245/45-16 Toyo RA-1 with 5k+ street miles, 15+ autoX and 3 HPDEs. Perhaps a little more wear on the outside edge due to hard cornering but generally nice even wear.

The tread width of the 245/45-17 is only .5 wider than the OEM 225/50-16 S02s and the stagger is essentually preserved (with non OEM 205/55 fronts) so I think the 245/45 is a better coice than a narrower 225/50.

JDM Baller

NYS2k - You mentioned that with S03's, the 245/45/16 does not have even tread wear. I am planning to purchase these tires this fall and am interested in what you posted. Are you asserting that the 225/50/16 S03 (since you have this tire) is actually BETTER on the stock 7.5 than 245 width?

I am inclined to agree with you for the following reason. On my 240SX, I had 16x7.0 rims and decided to try 225/45/16 Toyo T1-S's. Although they gave good straightline traction, something wasnt right in cornering. I also played with tire pressures.

Later, I tried a smaller size. 205/50/16 Bridgestone RE750's. My traction and handling skyrocketed. Not only was I able to use ALL of the tire (I noticed that center wear as well on the Toyo's) but the stiffer sidewall decreased all of the rollover that I experienced with the Toyo's.

Elistan

[QUOTE]I don

JDM Baller

I know that many of the people that are looking at the 245's, are looking at ONLY the tread width. For example the 225/50/16 in S02 (S2k spec) is 8.5". The design on the 225 tire is to MAXIMIZE the tread width on that size. In my opinion, getting a tire that is wider, but yet has equal or more tread width, does not mean it has the same or more of a contact patch.

Let's take the S03 for example. The tread width for the 225/50/16 is 8.3" but the tread width for the 245/45/16 (which we would use according to the sticky) is 9.1". Does this mean that you get more lateral traction since you have a wider tire than stock S02? No it does not.

At this point, you are experiencing the crowning affect because the tire is simply too wide for the 7.5" wheel. Why else do you think when you move up to a 9" wheel, you only use a 255 width tire? Because that is the correct width (measuring rim).

Lets take another example. The Goodyear Eagle F1-GSD3. This tire has a significantly narrow tread width than the S02's or S03's. 225/50/16 is only a 7.3" tread width. 245/50/16 (yes I know its not the correct size, but this is an example) is 7.9" tread width. By the logic of matching tread widths, are we to get a 265/40/16 (if they made it) to go onto the 16x7.5? Of course not. There is too much tire for that small of a wheel.

I'm sure there is evidence that proves 245/45/16 is better than 225/50/16 on some particular tires on our 7.5" rim. However this is not ALWAYS true. Wider is not always better. I have a friend with a VR4 (3000GT) and he put tires that were wider than the recommended width. He said because he wanted more tire to get more traction. However, looking at his tire, you can definitely see that the center was more worn and the contact patch was not maximized on that width. Sure he has the width, but the wheel was too small for it.

In the example of the S03's, which are a popular upgrade over the S02's, 245/45/16 does not appear to be the optimum size to get. I'm open to facts such as numbers to suggest otherwise. However, I'm not going to take an opinion simply because someone says "will the S03 grips better than the S02 at 245/45/16".. well has the 225/50/16 S03 been tested to prove that it grips worse?

Remember that different tires have different characteristics such as sidewall stiffness, tread width, etc. All these affect handling. Making blanket statements that 245/45/16 is the same as a 225/50/16 S02 is ignorant.... also why hasn't the TireRack website been changed to reflect this new information? I am still seeing 225/50/16 sold as the stock rear size. Stores here locally sell 225/50/16 as the recommended size as well. So since 245/45/16 is what many of you believe to be the correct size, then TireRack needs to stop selling incorrect tire sizes. S2ki only represents a FRACTION of the S2k owners in the world.... so I guess everyone except for members of this forum are all rolling on incorrect tire sizes if they dont get stock S02's.

NYS2K

TubeDriver wrote :

And:

[QUOTE]

Pierre S2K

NYS2K stated:


Guy,

You don't need to be so humble as your basic premise relating rim width to tire performance is as sound as it gets.

I, for one, admit, for the benefit of the board members, that I too easily succombed to the propaganda on this board and went for the 245-45-16 S-03s regardless of the fact that I knew very well that 7.5" is at the lower end of the suggested rim width range for this tire and that this very likely meant center tread wear. When I installed them, however, I was very happy with the initial results as the tires did not bow out too much from the rim. The initial satisfaction quickly turned to dissapointment as the center of the tread continued to wear quicker than the sides despite that I tried different pressures to at least slow down the process.

Now, for you others who have worn the 245 S-03s, please share your comments on tread wear, be it good or bad, so that we can get some kind of concensus here!


Pierre

S2kSi

I'n running Goodyear Eagle GSD3 225/50/16.

Tyre wear is very even after 5000 miles.

There does seem to be less outright dry grip at the the rear than with the S02s, but this just means more oversteer, which I enjoy. Also the Goodyears are much, much better in the wet.

In my oppinion there is no need to go for 245/45 at the rear when using non S02s. Nobody seems to feel the need to run 215/50s at the front instead of 205/55s.

Plus if you use anything other than 225/50, you are using a tyre that is outside the manufacturers specification, which may invalidate your insurance.

CoralDoc

I find it very interesting that this thread popped up. I was working on a friends car that I co-drive in autocrossing, and his rear 245/45/16 SO3 PP tires also exhibited excessive center tread wear. He even had relatively low tire pressure in it - about 26 psi.

Since this thread has been discussing even tread wear, I suggest that we also need to consider handling balance. The two are related, but like NYS2K first mentioned, non-optimal contact patches may diminish the extra grip expected by wider tires. It would be very interesting and instructive to arrange a test day with rear tires of different tread widths using a standard front tire to see how balance is affected. Jim, are you following this thread? I think The Tire Rack has an excellent tire testing facility and perhaps a test day could be arranged.

I suspect that recommended tire width is more complicated than was first suspected and while certain non-OEM tires should be used in the 245/45/16 size, others, like the SO3 PP, should be used in the 225/50/16 size if even tread wear is the goal.

NYS2K

CoralDoc challenged:

I really don't think that we can count on Jim to help us in this matter, as he has already taken the position that 245 S-03s are the perfect replacement for the OEM S-02s. It would now be very embarrasing for him to go back on his opinion, don't you think?

Guy

N.B. this is yet another call to users of the 245 S-03s: do they wear more in the center; YES or NO?