Michelin 305/35/19 Tires

[Brian Z.]

GT350 owners with the tires listed above I have a few questions. First, as background I'm looking for new tires for my forged 19x11 wheels and I'm very interested in that particular size for a number of reasons. I read that Michelin created this size just for the GT350.

However, I currently have Michelin Pilot Sport PS2 tires and they suck because their sidewall is too soft and it requires me to run 37-38lbs of pressure in the rear to keep them from wobbling/swaying, and that makes the ride worse, which is important since I daily drive my 2016 Mustang GT. This is a very common problem for this tire (and the Super Sports) and there are threads on corvette, gtr, mustang and other forums documenting this phenomena. One corvette thread is entitled "death wobble" which I found amusing, but it is in fact very unnerving. Now some people claim it's just the "Ferrari spec" tires and not the "Porsche spec", but considering the cost of these tires I don't want to make another costly mistake.

So my questions are:
1. How do you like these tires on your GT350?
2. What air pressure do you run in them?
3. Are they somewhat compliant on typical crappy city streets?

Thanks in advance!

Sponsored

 

[enzo101]

1. Tons and tons of grip. Have yet to break them loose. They are a soft compound as well.
2. I forget but will find out when I get home.
3. Yes and no. They handle bumps and rocks fine (sticky compound so they grab pebbles) they do follow road grooves but that comes with a set of wide front tires. I like them but I'd wait until a few other members respond to this thread.
Best of luck!

 

[nastang87xx]

Super Sports in general have some clever tricks. First off, the tire walls are definitely stiffer than your average Max Performance summer tire. They also incorporate two different compounds in the same tire. If I remember this correctly, the outer ribs of the tread are a very sticky compound like you'd find on a lower tread wear tire like Extreme Performance tires to help with cornering stability. The inner treads are a more traditional Max Performance-like compound that helps the tire last longer and improving ride quality.

 

[Hack]

However, I currently have Michelin Pilot Sport PS2 tires and they suck because their sidewall is too soft and it requires me to run 37-38lbs of pressure in the rear to keep them from wobbling/swaying, and that makes the ride worse, which is important since I daily drive my 2016 Mustang GT. !

AFAIK there's no problem with the sidewalls on PS2 tires being soft. In fact, they are stiffer than most tires in order for them to provide good handling characteristics. I'm guessing that the effect you are talking about is tramlining, which is actually due to the sidewalls being stiff and the tire being wide and square in shape. The tires interact with the depressions in the road to steer the car. You can feel an effect of ruts in the road pulling the car one way or another. Yes it can be disconcerting, but it's also normal and there's no problem. It just means that you are running wide, performance tires on your car.

By over-inflating the tires you are making them "belly out" in the middle of the tread, which reduces the tramlining because the edges of the tires become less square in shape. The negative consequences of this are that the center of the treads will wear out more quickly, and you will get a lot less ultimate grip from the tires.

 

[Brian Z.]

AFAIK there's no problem with the sidewalls on PS2 tires being soft. In fact, they are stiffer than most tires in order for them to provide good handling characteristics. I'm guessing that the effect you are talking about is tramlining, which is actually due to the sidewalls being stiff and the tire being wide and square in shape. The tires interact with the depressions in the road to steer the car. You can feel an effect of ruts in the road pulling the car one way or another. Yes it can be disconcerting, but it's also normal and there's no problem. It just means that you are running wide, performance tires on your car.

By over-inflating the tires you are making them "belly out" in the middle of the tread, which reduces the tramlining because the edges of the tires become less square in shape. The negative consequences of this are that the center of the treads will wear out more quickly, and you will get a lot less ultimate grip from the tires.

Hack thanks for the response but it has been pretty well documented that at least some PS2 and SS tires have softer side walls and cannot handle the weight of our cars. I understand trammeling, but this is something much different. Again, I'm not saying all PS2's and SS's suffer from this, but if you do a google search you'll find owners of heavier cars like ours having the same issue I described, even some lighter cars like vettes. I'm guessing since these 305/35/19's were specifically developed for the GT350 that they should be fine for my car, but that's why I wanted to get some feedback from GT350 owners before dropping major coin on new tires.

 

[xt6wagon]

you could also use 305/30R19 if you are worried. Its also a common size.

 

[Brian Z.]

you could also use 305/30R19 if you are worried. Its also a common size.

Thanks, but that's what I have now with the PS2 and they just look to thin to me, so I'd like a little more sidewall with the 35 series. Really I think the GT350 wheels and tires are perfect from an aesthetic standpoint, and it appears from all the rave reviews that the tires perform great too. If no one is needing to run 38 lbs of pressure with their michelin 305/35/19's then that means I shouldn't run into the problem I (and many others) have had with the PS2's and SS's.

I appreciate everyone's replies.

 

[krt22]

I dont even run 38PSI in my commuter car, that is definitely way too high for any sort of grip.

 

[Gibbo205]

I spoke to Michelin a few days ago and told them I wanted to use their super sports and informed them in the size I want they only come with NO Porsche approval or K1 Ferrari approval.

I said my car is a Ford Mustang so is it safe to fit these tyres. The response was ONLY fit the NO Porsche tyre, DO NOT fit the K1 Ferrari tyre.

 

[Trackaholic]

The Vette's super sports are run-flats, so if they are having issues it would probably not be due a sidewall that is too soft (unless this is for aftermarket tires where poeple are ditching the run flats).

I run ~35 PSI in my tires, but dropped down to 28 for my track day. I didn't notice any abnormal wobble before the tires heated back up.

I also have a set of super sports for my 350Z (245/40-18) and I run 35 PSI in those and they seem to be fine.

The ride of the GT350 is very good on city streets, but mine has the magnetic shocks so I'm not sure how much of the ride is due to the shocks.

IMO the super sports are a very good tire. Not sure I'd want to pay for them all the time though!

-T

 

[Rogue]

I daily drive Michelin PSS on a 911, no better performance street tire for sale. On the track you can do better with R compounds of course, but considered pretty decent for track use also.

 

[Brian Z.]

I spoke to Michelin a few days ago and told them I wanted to use their super sports and informed them in the size I want they only come with NO Porsche approval or K1 Ferrari approval.

I said my car is a Ford Mustang so is it safe to fit these tyres. The response was ONLY fit the NO Porsche tyre, DO NOT fit the K1 Ferrari tyre.

Gibbo thanks, that's consistent with my experience and what I've read on various forums. I must have the Ferrari spec, unfortunately. So do the gt350 specific size come in the two different specs?

 

[Hack]

Hack thanks for the response but it has been pretty well documented that at least some PS2 and SS tires have softer side walls and cannot handle the weight of our cars. I understand trammeling, but this is something much different. Again, I'm not saying all PS2's and SS's suffer from this, but if you do a google search you'll find owners of heavier cars like ours having the same issue I described, even some lighter cars like vettes. I'm guessing since these 305/35/19's were specifically developed for the GT350 that they should be fine for my car, but that's why I wanted to get some feedback from GT350 owners before dropping major coin on new tires.

Never heard of it. I ran PSS tires on my 2011 GT and they were really great. Super good grip and great handling. No problems at all. I also researched them quite a bit online before buying and saw nothing but positive reviews. Of course this was a few years ago. I would highly recommend pilot super sports to anyone for a sporty car if you want both straight line grip and good cornering. They are really good in cooler weather and the rain as well. Expensive, but really good tires.

Thanks, but that's what I have now with the PS2 and they just look to thin to me, so I'd like a little more sidewall with the 35 series. Really I think the GT350 wheels and tires are perfect from an aesthetic standpoint, and it appears from all the rave reviews that the tires perform great too. If no one is needing to run 38 lbs of pressure with their michelin 305/35/19's then that means I shouldn't run into the problem I (and many others) have had with the PS2's and SS's.

I appreciate everyone's replies.

You're worried about the stiffness of the sidewall but you are thinking about going to a taller sidewall? Doesn't compute for me. Don't you think a shorter sidewall will tend to be stiffer?

 

[Brian Z.]

Never heard of it. I ran PSS tires on my 2011 GT and they were really great. Super good grip and great handling. No problems at all. I also researched them quite a bit online before buying and saw nothing but positive reviews. Of course this was a few years ago. I would highly recommend pilot super sports to anyone for a sporty car if you want both straight line grip and good cornering. They are really good in cooler weather and the rain as well. Expensive, but really good tires.




You're worried about the stiffness of the sidewall but you are thinking about going to a taller sidewall? Doesn't compute for me. Don't you think a shorter sidewall will tend to be stiffer?

Absolutely but I think the sidewall composition on the gt350 specific tire is far stiffer than on my ps2 tire. My guess is that the gt350 tire has a similar sidewall composition to what was on your 2011.

A lot of guys on a gt500 forum had pilot super sports, and with the same suspension, some had no wobble and others had it badly like me, and the wobble SS were all Ferrari spec, the ones without were Porsche spec.

 

[combustor]

5 track days on the PSS so far and no "wobble". running 28 PSI like Ford recommends and it seems spot on. Edges are looking a little ragged but they are still performing great. I plan on replacing with the same tire (can't wait for race compound brake pads though)

Sponsored