New APEX VS-5RS Wheels - Tire Fitment Inquiry
 

Greetings Gang,

I recently purchased a set of wheel from the APEX 19" Wheel Group Buy, and I am having troubles deciding on new tires. The wheels in question are the VS-5RS in the following fitment:

19 x 9 ET50
19 x 12 ET63

The tires I am leaning towards ordering are MPS4S, but I am stuck between (2) size for the rear tires because I have heard and read that the MPS4S run on the wider side, and I am on OEM Sport PASM suspension and do not plan on coilovers or modifying the rear geometry via aftermarket suspension components that allow for eccentric changes. The tire sizes FOR THE TIRE IN QUESTION are the following:

315/30-19
325/30-19

Basically, I am curious if anyone is running the 325 MPS4S successfully on OEM suspension with Sport PASM, ie., no rubbing, etc. I have been in contact with APEX CS and they have been EXCELLENT in responding, but they do not have any anecdotal data, and will not give any specific counsel on which size I should go with. I believe the 315 is safe but worried I may be missing out by not going 325, but also worried that the 325 may need additional parts etc to run without issue. Any help would be much appreciated here. Thanks in advance!

it wasn't listed on one of the fitment guides? - https://support.apexraceparts.com/hc...673053-Porsche

I see some 325's in there for at least a C2/C2S. I didn't probe any further.

^ yep, in Apex’s guide and lots of people on the forum running the 325/30-19.

OP, Search Google for “997 325/30-19 Rennlist”.

Pardon, does that mean you are running the same spec rear wheel on 325's? If so what brand? I hear the Conti Extremecontact Sport 02 runs narrower without issue, but not the tire I am looking to run. Please advise!

Thanks for the advice. I've read up a TON and even called a few speed shops, but most of the 325/30 19 on APEX's guide are 997 GT3 and not .2 S cars.

I am also asking specifically about the MPS4S I. The 325... I gues I should have also mentioned that it is for a 997.2 S. Do you have any experience w said wheel spec and tire... 19x12, 325/30-19 MPS4S?

I would GREATLY appreciate any intel. Cheers!

The reference was to a Carrera 2 or S. Apex lists what wheel and tire combinations are direct fits vs. requiring shims/camber plates on their support page. I used their page for the 718 GTS/GT4/Spyder fitment to grab some wheels at an alternate size/width and they fit as advertised.

I have pasm, HR springs and 325/30/19 tires. No problems and it's pretty low.




edit: typo

ok, great! Are you running MPS4S tires?

Any feedback on how the car handles/drives after moving to such a wide rear? At this point I'm already all-in... just curious. I hope you can share. Thanks!

I'm running 255s and 325s on my NB c2s. You can better match the 255 fronts to the 325 rears in rolling circumference to keep the ABS, PSM, and AWD (where pertinent) happy.

Thanks Petza!

So I've completely decided against 325/30 19 tires in the rear. Now my dilemma is 305 vs 315 in the rear. Since I am going with the 245/30-19 to accommodate the wider on a 9 x 19 wheel in the front, should i go up to the 315/30 in the rear, or just stick w 305/30 on the 12 x 19 wheel? 12 x 19 with 305/30-19 is the OEM GT3 tire size.

My worry is that by only going wider/larger in the front it will make the nannies on the car spaz out.

I am probably overthinking all of this, but I live by measure twice, cut once. Help please!

What makes the nannies "spaz out" is a difference in rolling circumference between the front and rear. The car will accept a difference of about 2%-3%.

Go to the website of the tire manufacturer you're going to use and lookup the tire specs for that model. Compare the diameter or circumference spec for the sizes and pick sizes that are the most similar and make sure those are within 2-3% of each other.

That aside, with everything else being equal (sway bars, suspension tuning, etc) adding or reducing more front grip vs rear grip with change the understeer/oversteer characteristics of the car. Going to a wider rear tire like a 315 or 325 without changing the front tire to something larger than the stock 235 will make the car understeer as you've increased the rear grip relative to the front grip. If going to a 315 rear you will want a 245 or 255 front (whichever gives you the better match in diameter).

I think you're overthinking it. If you're not doing 325, go with 305 since that seems to have a lot more options for tires than the 315. Also, your 245's in the front should be at a 35 aspect ratio, not 30. 30 will change the ratio of the front to rear tire diameters and will likely mess with the nannies.

I hear and understand what you are saying. I am safe with both 245 front and 305 and 315 rears. I just wish there was some feedback from users here on either for the 19 x 12 rears. It doesn't seem like the 315 is too popular of a fitment for some reason.

Yes, you are correct on 35. That was a typo.

Now my predicament is 305 vs 315 on the rears. Also TR has both sizes for MPS4S.

Identical offsets,
325/30/19 19x12 rear
255/35/19 19x9 front
MP4S - Eibach lowering springs on PASM.

don't do anything else


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