Pirelli PZero 305/30/20 (99Y)

[13M5F10]

I wanted to put this out there. If you ever plan to upgrade yours rears to 305 PZero, make sure you go with the 99Y loading and not the 103Y.

The 99Y fit beautifully and flush with the stock 343Ms. However, 103Y will bulge real bad and will affect handling. I got an amazing deal for the 103s and jumped on it but quickly realized the mistake I made. Ended up going back to 99Y real quick.

I wanted to out this out there as I've seen others pick up 103Y on here.

[gblansten]

Good to know. I would have had tears as well with the 103y setup.

[13M5F10]

Originally Posted by gblansten

Good to know. I would have had tears as well with the 103y setup.

LOL.. Corrected tears to rears. I did have tears from the ugliness of the bulge and the poor handling.

[Vic55]

So why does this happen? I understand the load rating measures but is the tire that much wider = bulge = viagara.

[Grumpywings]

The bulge is real, people.

[Grumpywings]

I bought 2 sets, so I had to rebuild my wife's truck to accommodate them It's the right sidewall for a hot rod, but not for a touring car.

[apsuard]

I have the 99Y on my 11 inch wide HRE and one thing to note is that they are not XL. They are standard load tires. Per Tire Rack they are a very wide tire for a 305 however. Even wider than the MPSS.

[13M5F10]

Originally Posted by Vic55

So why does this happen? I understand the load rating measures but is the tire that much wider = bulge = viagara.

The larger the load on the tire, the larger the contact patch.

I currently am running a 99Y and there is a significant difference in fitment, handling, and aesthetics. Its odd I know but on the PZEROs it makes a difference.

[13M5F10]

Originally Posted by Grumpywings

I bought 2 sets, so I had to rebuild my wife's truck to accommodate them It's the right sidewall for a hot rod, but not for a touring car.

Let me know when you need more. I know a guy that sells them for $75 each on Northwest Highway. LOL

[13M5F10]

Here are picture of the 99Y. As you can see it sits rather flush with the wheel. Also has a nice lip protection. The 103Y bulges so badly

[Grumpywings]

The 103Y doesn't just bulge more because it's wider; has a completely different sidewall. Even if it's on a 12" wheel, it still won't look the same as all of the front tires.

[13M5F10]

Originally Posted by Grumpywings

The 103Y doesn't just bulge more because it's wider; has a completely different sidewall. Even if it's on a 12" wheel, it still won't look the same as all of the front tires.

Thanks for the side by side comparison. I agree, on my 12" wheel it still bulged and still didn't look the same as the fronts. Seems like a different design overall

[MCarsFan]

Originally Posted by 13M5F10

Thanks for the side by side comparison. I agree, on my 12" wheel it still bulged and still didn't look the same as the fronts. Seems like a different design overall

Grumpywings have you not switched over to 99Ys ? Thought you did after we met up?

[scott135i]

The 305 PSS on the stock 10" M5 wheels sit the same as your 103Y 305 P Zeros. Hella bulge. I like it oddly enough. I'll know in a few days if it's negatively affects handling dynamics but have them pumped up a bit so who knows. #rimportector

[13M5F10]

Originally Posted by scott135i

The 305 PSS on the stock 10" M5 wheels sit the same as your 103Y 305 P Zeros. Hella bulge. I like it oddly enough. I'll know in a few days if it's negatively affects handling dynamics but have them pumped up a bit so who knows. #rimportector

Yeah the PSS run wider naturally so I would have expected that. This is a different kinda bulge than the PZERO and I don't think it will affected handling much.

The PZEROs had a bulge I've never seen before. People thought my tires were low. It was like a big U all around the wheel. A lot of side to side flex was happening and car was spinning tire a ton

[scott135i]

Originally Posted by 13M5F10

Yeah the PSS run wider naturally so I would have expected that. This is a different kinda bulge than the PZERO and I don't think it will affected handling much.

The PZEROs had a bulge I've never seen before. People thought my tires were low. It was like a big U all around the wheel. A lot of side to side flex was happening and car was spinning tire a ton

Thanks for the context. Just took the car out for 50 miles. Feels perfect. No sidewall roll (PSI up to 38-39 cold inflation). And my buddy ARC550 has the 305 PSS on his 10.5" M6 343's and the side profile looks nearly identical.

Did you happen to take any pictures with the 103Y 305 PZeros?

[13M5F10]

Originally Posted by scott135i

Thanks for the context. Just took the car out for 50 miles. Feels perfect. No sidewall roll (PSI up to 38-39 cold inflation). And my buddy ARC550 has the 305 PSS on his 10.5" M6 343's and the side profile looks nearly identical.

Did you happen to take any pictures with the 103Y 305 PZeros?

I had intended to for this thread but got sidetracked at the tire shop.

This is what I have right now and doesn't look as bad as it really did look.

[M6-Coupe]

MPSS 305/30/20 with M6 343M rims on M6... no rubbing issue BTW

[HappyMan]

So, boys which tyre is the best suited for our cars? Pzero or Mpss? Mine came with Pzero. While they were new traction was a bit of a problem but after 5.000km traction is only problem in 1 gear. In second gear at 70km/h if I go full throttle during dry and very warm day there is no traction issue, just hooks. Is that normal? I was thinking maybe my car makes less power compared to other stock M5's or is it something wrong with the car? Because before in second gear at 70km/h if go full throttle it used to burn out like crazy. Can someone chime in please? Cause I'm going nuts sometimes about that.

[13M5F10]

Originally Posted by HappyMan

So, boys which tyre is the best suited for our cars? Pzero or Mpss? Mine came with Pzero. While they were new traction was a bit of a problem but after 5.000km traction is only problem in 1 gear. In second gear at 70km/h if I go full throttle during dry and very warm day there is no traction issue, just hooks. Is that normal? I was thinking maybe my car makes less power compared to other stock M5's or is it something wrong with the car? Because before in second gear at 70km/h if go full throttle it used to burn out like crazy. Can someone chime in please? Cause I'm going nuts sometimes about that.

I have 800+ HP and my PZEROs hook with minimal spin. After a few thousand miles I will be back to no traction again lol

What you are experiencing is perfectly normal. These are summer tires and the rubber gets stickier with the heat. Stickier tires = better traction.

MPSS and PZeros are great tires.

[Jens Mariager]

Hi there
Just thought the 99y and 103y code is that not only speed ratted to 300km/h?
should it not be a ZR??

[13M5F10]

Originally Posted by Jens Mariager

Hi there
Just thought the 99y and 103y code is that not only speed ratted to 300km/h?
should it not be a ZR??

The Pirelli PZero are ZR rate. Y is also a speed rating. The 99 Vs 103 is the load rating.


Y - Up to 186 mph
Z - 149 mph and over