You will love those tires. Have them on my 575M and they are such an improvement in everything it is just amazing. Especially since you were able to get K versions designed for Ferraris.
Hello Terry, Good that you are discussing this since I'm changing my tires soon. I've seen that mentioned before but don't know where. I believe there are K and N variants? For 612 sizes, I've searched and found only N (Porsche specs?). Will it be a problem? The difference is on the compound? Design? Thread? Thank you.
Ricardo- No problem at all. The Porsche spec tires will work just fine. On the 599s, you really do want the K2 (F12) rears instead of the K1s (GTO) because the K1s have less tread depth.
Hi Need some advise re tyres. I order the rear 315s for the GTB - but been told by Ferrari Service that this is not recommended as it will have an issue on traction control / manniteno and TPMS. My question is - has anyone faced this issue and how realistic or the points raised by Ferrari service. Also does this invalidate the Power Warranty? Many Thanks Shaan
Shaan- They are wrong. The front to rear differential on tire diameter has to be 4-5% before it starts causing problems with ABS/stability control. 305/35 20s are 28.41" in diameter and 315/35 20s are 28.68", so the difference is only 0.95%. This difference is so small it has no affect on ABS/SC. A clear cut case of them knowing a little about the subject (changing F to R tire diameter differential can cause ABS/SC problems), but apparently not enough to understand details of how the system works. Plus there are several owners running those sizes with no problems.
No problems here on the 315s. Terry, is the difference between K1 & K2 just the tread depth? I've been on the K1s for a few years now and have only enjoyment of the tires. I usually do not drive in the rain so I don't think the tread depth will not be much of an issue.
Not sure if the compounds are the same or not. Probably very similar since they are both for high powered, front engine V12s. The tread depth issue is strictly one of tread life, about 30% more tread wear possible on the K2s, assuming the compounds are similar. So they would work better in the wet for a longer period of time. In the dry, the less tread, the better in general, which is why the GTO came with less tread.
The width of the 315/35R20 K1 thread is also 0.5" wider than the K2. So it would stand to reason that the K2 is also better in the wet due to it being narrower.
The section width of the K1 and K2 is the same @ 12.6". But the tread width is 11.5" for the K1 and 11" for the K2. If you look at a spec sheet from Michelin or on that Tirerack page, you can see that often the OEM tyres use different tread widths, and on occasion diameters and section widths as well. Another example is the 255/35R20 K2 vs. the "normal" 255/35R20. The K2 has a tread width of 10" while the non-Ferrari tyre has a tread width of 9.2". Again the K1 285/30R20 matching the 315 K1 has a tread that is 9.5" wide, while the normal 285/30R20 has a tread that is 10.2" wide. Both tyres have a section width of 11.4" on a 10" rim, and like the 315 K1, the 285 K1 has a tread depth of 7/32" compared to stock 10/32". As to what they do with compound, who knows. But I would not be surprised if the tyres for the 599GTO had a different compound better suited to run hotter and with more bite. If you want to see something really funny, look up the tread width of the MPSC2 245/35R20 K1 Speciale front vs. the MPSC2 245/35R20 N0 991 GT3 front. The section width is the same, but that cannot be said for the tyre tread itself. And just to finish off the confusion for good measure, the MPSS 305/30R20 has a wider tread than both the MPSS 315/35R20 K1 and K2 @ 11.8" with a section width that is narrower than both @ 12.3"...
Thank you Terry, DK and everyone for a very informative thread. Ken they know way more about this than I do but I would recommend these tires because they not only have better grip but also have better ride quality as well. I think if you plan to drive a lot in the rain you probably want the K2 tires. All I can say is the K1 tires I have on my GTB - originally without HGTE suspension but now with the HGTE- have been such an improvement over the MPS2 tires on this car that its nearly a revelation. I used to be able to spin the tires in the first 3 gears. Now, I can still do it in 1st if the roads are cool but if they are warm and the tires warm, they just grip. This also helps the brakes and I even feel like they have better steering feel and response. It was like getting almost a version 2.0 of my car.
That size fits fine. It is what's on my car. In fact, that pic looks like my car from the window tint to the GTO grill and the lower stance. EDIT: After a quick search of the OP's threads, I am almost 100% sure that is my car.
Interesting, now that the MPS4S replaces the MPSS, the K1 315/35 20s have 9.5/32" of tread where the old ones had 7/32".
Hi Terry, I’ve been away for a while hence no recent update on the 575 yet. I have a 599 HGTE that has just come out of storage and I suspect new tyres required. (The tyres are nearly 10 yrs old and the handling is frighteningly bad) Is the consensus still that the Michelin tyres are the better? Are they a summer only tyre or year round? Thanks.
