355 New Tires

I have been super happy with the Yokohama AD09 I installed last year on my 355.

They replaced some Michelin PS4S tires which are pretty much the "gold standard" of max performance tires. They do everything well and don't have any bad habits. They are a solid choice no matter what the car but work great on the 355. But to me, they were almost too perfect, and they can have a slightly numb turn-in feel. But mainly I just wanted to try something different.

With the Yokohamas being an extreme performance tire, I was expecting them to be a little noisier and a little harsher. And I guess they are but just barely. As a track-focused tire it was harder to get good reviews for them for use as street tires. They are actually pretty comfortable and have great feel and communication (which is more important than absolute grip for a street tire). They turn-in really well and they make a bit more noise than the Michelins when they do start to slide. They are fine cool but when they get hot you can feel the grip go to another level.


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michelins every time.

 

The Conti ExtremeContact Sport 02 seem to be the hot ticket, I have good experience with the previous version, especially in the wet. The P4S seems to be also be a good choice. I'm planning to put a set of the Contis on my challenge rims this spring.

https://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=329

 

Michelin Pilot Sport 4 S - as noted above, they are the gold standard for street max performance tires. You could try Michelin Pilot Sport Cup 2 tires if you wanted more dry grip performance, lower mileage durability, worse wet performance and really like the sound of sand and gravel being thrown up in the wheel wells as they are picked up by the tires and cast off.

 

Its also worth noting that there are multiple versions of each tire as auto manufacturers will work with tire suppliers to derive specific results for their cars. This video does an excellent job of highlighting the differences of a Michelin PS4S and Michelin PS4S BMW OEM tire.

The next time I replace my tires I would heavily consider one of the OEM versions, such as this BMW M4 version, of the PS4S on my 95 GTB.



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The 265s are the stock width for the rear tire. I use 295s as do many 355 owners.

 

Unfortunately Michelin and other tire manufacturers only produce OEM tires in sizes where the manufacturer requests them so sadly even though there are many versions of the PS4S in our 18" wheel size only the aftermarket version is available. I took a quick look on the Michelin website and while there are lots of choices in other sizes we only have the one in ours.

I was a bit too quick with thinking that we might have options...

 

Great question and you'll get a variety of responses.

My view is that tires are a critical portion of the driving experience and the single biggest factor in overall performance. But in answer to the specific question on aftermarket PS4S vs OEM PS4S I think there would be minimal difference in modestly aggressive street driving while keeping speeds near legal speed limits.

Emergency braking, speeding on a cloverleaf or a spirited drive on a winding country road well above the speed limits would be where I imagine the difference could be found outside of a track situation.

 

You just dialed in understeer unless you widened the fronts to 250mm; or raised the rear to dial in more oversteer.

 

I've kept only OEM sizes on my 95 F355 GTB so I can't truly comment on what it would be like with wider rears. I will say that I've felt the car to be very well balanced on the street and on mild 7/10ths track situations and I've not felt that rear grip would give me any more driving enjoyment.

 

Yes, of course that's true but it's not quite that simple. You have to look at the specs for each tire as there is a lot of variance. The 295 rears are wider but the front is also wider, even in the "same" nominal 225 size. So, the net gain in rear tire width is about half of what you would expect.

The 225 Michelin PS4S has an actual (tread) width of 7.7" and the 225 Yokohama AD09 has a tread width of 8.2", so +.5" front width gain going to the Yokohama in the "same" tire size.

The 265 Michelin PS4S has an actual (tread) width of 9.5" and the 295 Yokohama AD09 has a tread width of 10.5" so +1.0" rear width gain going to the Yokohama in the 295 width.

Therefore, I only gained about +.5" rear tread width with this swap relative to the fronts. I should also mention this is on wheels that are slightly wider than stock, so they better support the wider tire width as well.

 

This is all so academic. None of us are good enough drivers, or drive fast/dangerous enough on the street, for differences among high-performance tires to be noticeable. Not one of you would know what brand and model of tires are on your 355 if you couldn't read the sidewall. Let's not flatter ourselves. FWIW, my 993 has Sumi's and my 355 came with Michelins, and the 993's handling, turn-in, and steering feel are clearly superior. Nothing to do with the tires though, as they're functionally identical (except for price).

And no, we don't drive our cars hard enough on the street for tire tech to come into play. Only people with little or no track experience think they drive hard on the street.

 

Here I am at Lime Rock Park in 42F weather...








It was too cold for slicks so I switched to my Michelin PS4Ss.

At least I had some nice cold ram air to help my car along.



They're good in the rain too...


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When it comes to max cornering or braking grip, I absolutely agree with you.

But there are subtle differences in steering and cornering feel, and there are definitely differences in compliance between tires. There are also differences in how tires fit, as the nominal size is anything but standardized. I think that's the point of these discussions. Nobody is talking about lap times or max cornering G-forces here.

 

I agree with the sentiment. However, worth noting that an emergency stop is probably something that each of us experience on a semi-regular basis. Debris in the road, a deer darting across the street, the unexpected, etc.

In that situation a new set of high performance tires will noticeably outperform lesser tires, especially if they're replacing a mediocre tire compound that is now 5+ years old.

I recently replaced a set of 6+ year old Kumho Ecsta summer tires with Pilot Sport 5 tires on an older JDM car. Unsurprisingly the difference was enormous especially under heavy braking. But to your point, a set of Yokohamas, etc, would have been very similar.

 

Right, Mitch.

Here's a good guide we use at the track:


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Even on the street it is pretty easy to feel differences in tires, high performance or not. Even the difference in tire pressure is noticeable. No need for a track
Maybe not to you, but to some people its pretty noticeable