I just ordered a set of Michelin Pilot Super Sport tires for the SRT6.
Front 225/40/18
Rear 275/30/19

I saw from a search that FUBU bought a set about a year ago and was wondering if he or anyone else had comments. These are supposedly the OEM tire that Ferrari ships on the 599 and 458 and get lot's of love at Tire Rack.

I was set to buy either the Bridgestone RE-11 or the Yokohama Advan Neova AD08 in the same sizes. But the Michelins are classed as a "Max Performance" summer tire while the RE11 and AD08 are classed as "Extreme Performance" tires. With that designation comes a warning about these things actually getting brittle at low temps (as in cracking) and a tread wear rating of 180 vs 300 for the Pilot SS.

The Pilot SS appears to be a step down in ultimate performance from the other two but still a very good performance tire. So, likes? Dislikes?

Separate issue.....the tires coming off the car have been OK......Dunlop Sport Maxx TT
Front 225/40/18
Rear 255/35/19

But, the reason for the replacement is a front tire failure Friday night driving home from work. 3rd one to fail in about 20,000 miles. The first two were punctures. OK, luck of the drive.

But this front passenger tire was worn right through the belts on the inside edge. I mean worn to the point that I could collapse it with pressure from my finger. And right on the corner where the sidewall intersects the tread. Very hard to notice if the car is parked with the wheels straight. The driver's side showed no such uneven wear.

The car was aligned (by a dealer) when the Dunlops were installed. And this appears to be a pure alignment issue. So my questions are.....

1. Is this sort of uneven front tire wear common on the SRT6?
2. Is there anything particularly unusual or tricky to aligning this old Merc suspension?
3. Do these SRT6's have trouble holding an alignment, camber or toe-in? Can't believe caster has anything to do with this.

 

1. If the wheels are out of alignment, you will see the wear. I had this issue on my old N/A convertible, but went away after a proper alignment.
2. Shouldn't be, but you will need to find a shop that has the proper equipment from my experiences.
3. Do you have stock suspension parts? How many total miles on the car?

 

The suspension is completely stock. I bought the car with 17,500 miles on the odometer. That's when the Dunlops were put on. Today the mileage stands at 38,000. At this mileage I wouldn't normally suspect bushings or other components unless there was damage from impact.

The way this front passenger tire was worn, the alignment wasn't off by a little. The inner edge wore through both steel belts and the polyester cords. The outer edge still had about 5/32nds of tread left. The front driver's tire was wearing normally.

I was just curious if these cars had a habit of not holding an alignment or were abnormally sensitive to impacts from potholes and broken pavement.

PS - This does not appear to be a tire failure issue as in a belt breaking or manufacturing defect. The tire was physically chewed up from the outside.

 

I have the PS2's on the front and Super sports on the back of my Srt. I am very happy with both. Ive had no issue with uneven wear like that with stock alignments but recently went to max camber, still no issue. If your looking to save a few bucks im going to sell my 225/40/18 michelin PS2's for a wider front, shoot me a pm if your intrested

PS, was the car wrecked at all? I would get a lifetime alignment from Firestone and just get it checked every 6 months or so, mine was $150 but ive already had 3 alignments on me car in 6 months, the guys at the local shop are great here

 

Nope, no damage. As for the PS2's, I won't need them. As noted in the original post, I have a full set of Pilot SS on the way. Being delivered today.

I almost went with 235/40/18 Super Sports up front. But the stock size appears to have very little room at full lock and I've seen people complaining about rubbing at full lock. So, I stayed with the stock size on the wheels that steer.

I'm gonna try my Tire Rack installer for the alignment. They have top notch equipment and seem to be very sharp. Also, that way the same guys will be doing the tire install/balance and the alignment. Less chance for finger pointing.

 

You'll notice a difference in the side walls with the 40 and 30. When I changed mine I originally went with 235/40/18 and 285/30/19. I saw there was a noticeable difference and had the rears replaced with 285/35/19.

 

Yeah, I kinda figured that the rear 30 series are gonna look like black rubber bands on silver wheels compared to the 40 series up front.

But the 285/35/19 are pretty rare. Only the Michelin PS2 at Tire Rack, not a tire I want.

And at 26.9" vs 26.0" stock, that introduces a 3.5% (slower) speed error on a larger diameter that creates effectively taller gearing.

The 275/30/19 goes the opposite direction at 25.6" vs 26.0 stock for a smaller 1.5% (faster) speed error on a smaller diameter that creates effectively shorter gearing. I like that better directionally.

My only other option up front was a Pilot SS in 245/35/18. But that tire is 0.8" wider than the 225/40/18. I was worried about rubbing in tight turns.

My biggest worry isn't the weird difference in looks. I'm wondering just how much the ride will suffer and if I'll get the additional rear traction I want. I'm pretty certain it'll do what I want on smooth pavement. Not so sure about less than perfect surfaces. Just hope I'm not replacing bent wheels.

 

If you do the math with the 275/30/19 vs the 285/35/19 for the Pilot SS and the 3.07 rear end of the SRT6.....

The 275/30/19 with the 1.5% reduction in diameter equates to an effective 3.11605 rear end.

The 285/35/19 with the 3.5% increase in diameter equates to an effective 2.96255 rear end.

The difference between the two is a not insignificant 5.2% quicker tire for the 275/30. At least on paper.

At anything above a standstill the smaller tire should make the car accelerate faster with loss of maybe 2.5 mph at the top end.

Assuming you have more than enough torque to spin either tire, the 285/35 should have a traction advantage from a standstill.