PS2's - Two Different Speed Ratings

[Marv S]

So we're at Chelsea proving grounds at the VDF and Eric Heuschele, SCCA Champion and Supervisor of Vehicle Dynamics for the SRT Engineering asks something like, "ok, who wants to talk about Viper dynamics?" (Is he a great guy to have on the SRT team or what?)

Cliff notes: He then proceeds to explain the how Michelin works with them for hours and hours and hours to develop just the right tire for Viper. The mix of sidewall stiffness, etc. all yields a Viper specific tire that is measurably better than the same sized non-Viper Michelin tire.

Old notes: The C1 tag never came on any 17" Michelin tires so don't bother looking for it on those old mxx3 or xgt tires. The first it appeared was on the 18" Pilot Sports about 1999.

There won't be any PS2 335*17 size or 335*18 size that carry a C1 label. Like Luke said, they just are not going to develop specific label tires for a 10 year old car, prior generation car. The "Viper specific" tire focus will be on the current model sizes.


Sideline notes: You may recall that PS2 did not initially come out in 17" sizes and the VCA petitioned Michelin and Dodge to do whatever possible to offer those older sizes in their latest product lineup.

It is important to recognize is that Michelin is making a modern tire in those old Viper sizes so when you see Michelin reps at VOI it would be good to express appreciation of that.

 

[Y2K5SRT]

...so when you see Michelin reps at VOI it would be good to express appreciation of that.

And to Eric Heuschele as well - he and a host of other SRT VIP's are planning to be at VOI 11, as well as a few VERY well-known faces from the past. There might even be a tire vendor or two answering questions and exhibiting at the track. Should be both fun and educational!

 

[Luke@tirerack]

I just purchased a set of PS-2's form Discount tire, the fronts are the "95Y" M0 and the rears are (105 Y)... What does the (105 Y) indicate??

your front tires belong on a Mercedes Benz and are a diffretn speed rating than the rear tires which are the appropriate tires fro your Viper ...

M0 = Mercedes
C1 = Viper

 

[Abe Froman]

Thank you Luke and everyone for the replys... Im having Discount Tire replace them with the correct "C1", or should I say more correct replacement.

Luke, do the "M0" PS-2’s lack performance properties over the “C1’s” ?? Or, is it only the speed rating due to the 1/32nd more tread ??

 

[Luke@tirerack]

the C1 version offers better performance than the M0 version

 

[Abe Froman]

OK, Discount tire replaced my “M0” PS-2’s with “ZR (95Y)” but they don’t have the C1 indicator. Is this still an incorrect tire for the viper?

 

[MuscleJunkie]

OK, Discount tire replaced my “M0” PS-2’s with “ZR (95Y)” but they don’t have the C1 indicator. Is this still an incorrect tire for the viper?

The rears will be C1 Spec as that is the only type of PS2 you can get in 345/30 19 size.

The fronts "might" be a different story. You might not know which is which until you actually get the tire and look at it.

It will either have a C1 written on the sidewall. If it doesn't but it still has the (Y) speed rating indicator then you received the original PS2 which is better than the Mercedes spec PS2 (standard Y speed rating) but still not the same as the C1 spec tire. Luke explained it to me that the difference in these two is the tread compound on the C1 spec is stickier than the non c1 or Mercedes spec PS2 and made especially for the Viper.

On a side note - not sure what year you are putting these on. I just put a set of C1 spec PS2s on my 2006 Viper and have discovered there "might" be some concerns about switching from the ZP Run Flats to the PS2 on 2003 - 2006 Vipers. According to the SRT Engineers the suspension on our cars IS NOT tuned for the PS2s and if and owner of one of these cars (2003 - 2006) were to choose to switch from the ZP Run Flats to PS2s then they would have to change the following to achieve the same handling performance as the 2008 - 2010 cars

1. Different Springs (Damping Tuning?)
2. Different Shocks (Damping Tuning?)
3. The Front Bar
4. Alignment

The SRT engineers claim that the 2003-2006 suspension is specifically tuned for the ZP Run Flats and some sort of performance (not sure exactly what, how or how much) might be compromised on these cars by switching to PS2s if you do not change out the Springs, Shocks, Front Bar and Alignment to 2008 or above spec.

I can say that I notice a HUGE improvement in ride quality and noise reduction with my new PS2s over the run flats but I would be curious to know just what I have given up (in the SRT Engineer's eyes) by making this switch without changing out the previously mentioned items.


If you continue to run into issues with Discount Tire, Viper Parts of America has C1 Spec PS2s with FREE shipping and you would be supporting the VCA with your purchase. There are also other supporting vendors like JonB of Parts Rack who can help you out and answer any more detailed questions you might have. JonB helped me out with my purchase and I cannot say enough about how helpful and knowledgeable he was during my tire purchase.

Hope this helps you out.

 

[Abe Froman]

MuscleJunkie, the information you have provided is great help. I’m purchasing from discount tire only because I’m cheap as “Hell”. They provided the best price, my four (4) tires were $1,312.00 out the door including lifetime balancing and the road hazard replacement warranty. Thank you again for the info...

 

[MuscleJunkie]

MuscleJunkie, the information you have provided is great help. I’m purchasing from discount tire only because I’m cheap as “Hell”. They provided the best price, my four (4) tires were $1,312.00 out the door including lifetime balancing and the road hazard replacement warranty. Thank you again for the info...

Wow - that is a GREAT price. Let us know how it all works out once you receive them and if they are the C1's or not.