I have decided Michelin PSS is the way to go (newer technology and lighter tire) 275/40R18 and either 235/40 or 225/45 As mentioned earlier 235/40 will be closer to 0.9610 ratio (0.9527), and 225/45 (0.9741) I have read in the past that increasing the grip by widening the front tire without increasing the rear tire can produce oversteer. (Just like a wider rear tire would produce understeer if the front isn't changed) How valid is this argument for small increments like 215 vs 225/235??? At the end is just 1-2 cms Sent from my iPhone using Tapatalk
If you stick to the same compound front and rear, I wouldn't worry at all about going with the slightly wider front tire. Most Ferrari and Porsche are setup from the factory to have understeer (saver for most drivers on the street), so if anything you'll get a bit more of a balanced setup with wider front tires.
I thought you listed 225 front 285 rear with PSS. Wouldn't that keep the ratio (front to back width) similar to the stock 215 and 275?
225/45 and 285/40 would be the closest to OEM but there isn't PSS available in that combination (no 285/40) actually only the Continental tire is available in that combination.
Sorry for the confusion, there is PSS in 225/40 (not 45) and 285/35 (not 40) This setup is still very close to OEM 0.9610 (at 0.9698) but the reason I discarded that combo is because the rear tire is the smallest diameter of all the options and it will increase the speedometer error another 3%.
Thanks to all for putting the useful information about tire options in this thread! I'm still a bit confused. It seems like MPSS is available in both 225/40 and 225/45 (at least in Europe): http://www.michelin.co.uk/tyres/michelin-pilot-super-sport#tab-tyres-benefits Do I interpret this incorrectly? The listed specs of the tires is different: 225/40 is listed as load 88, speed Y and has a 'B' rating concerning wet weather 225/45 is listed as load 95, speed ZR(Y) and has an 'A' rating for wet weather Are these fundamentally different tires and is one of them less suited for a 360? I'm now thinking about MPSS 225/40 and 275/40 if the mentioned 225/40 is suited for fitting on the 360. I'm still a bit concerned though about damaging my front fenders. The car is lowered, the fenders are not rolled and given the distance between the current stock sized tires and the fenders I'm already very surprised that there is no fender damage yet. I've searched for info on this forum on this subject and have seen that it had been discussed many times already but unfortunately without a uniform conclusion. If someone can give a definitive opinion about whether I would run a significant risk of damaging the fenders on my lowered 360 with the above tires … please don't hesitate to reply to this message
You are correct there's MPSS in 225/40 and 225/45 the problem is 225/40 goes along with 285/35 not 275/40 If you use 225/40 and 275/40 the ratio will be 0.9407 and you will have ABS issues. And there is no 285/40 in MPSS to match the available 225/45 You can do all the combinations you want as long as the ratio is closer to 0.9610 as possible (no more than 1.5 in my opinion so 0.9610+/-0.0150, I have 0.9414 now and I do have ABS problems) and you do not decrease the diameter of the rear tire that much or you will have a bigger speedometer error. The diameters for all the tires mentioned here are Front OEM 215/45 25.62 225/45 25.97 225/40 25.08 235/40 25.40 Rear OEM 275/40 26.66 285/40 26.98 285/35 25.86 295/35 26.12 For example OEM is 25.62/26.66=0.9610 For me the best Michelin PSS combination is 235/40 and 275/40 that will give you 0.9527 (only -0.0083 difference) and the speedometer stays the same. As mentioned before The 225/40 and 285/35 keeps a good 0.9698 too but the speedometer error increases by 3% (25.86 vs OEM 26.66) Regarding fenders, I have 235/40 right now and I do not have any issues rubbing even in hard cornering, and my front wheels are actually 8" vs OEM 7.5"
As said, what you want is either 225/45R18 or 235/40R18. Fernando what's the offset on those 8"x18" front rims you mention? Adding a ½" inch to the rim only increases the section width of the tyre by 0.2" i.e. .1" on each side. If your ET is wastly different from the OE 7.5" wide rims, that can make more of a difference when it comes to rubbing on the fender lip.
My wheels are: 18X8+31 front 18X10+32 rear I believe (found in another thread) starfish wheels are 18X7.5+31.5 18X10 +39 Using an offset calculator my front wheel edge extends an extra 6mm, and my tire is 20mms wider than stock, but the diameter is less than OEM 25.40 vs 25.62, I am not a wheels expert but I guess the tire being smaller prevents the rubbing of my wheel even thoug its stance is wider?? All I know is it doesn't rub.
Thanks Fernando for all the info! Unfortunately I can't find the 235/40 in Europe yet. This size is also not listed as an available size on the UK Michelin website making me fear the worst. I wonder what high performance tires people put on the stock rims of their 360 in Europe. It certainly doesn't seem to have created such a demand for mpss tires that michelin has elected to include a matching pair of tires in their line up.
Just put MPSS 225/45R18 on if you can't get 235/40R18. They are most definitely available. Have you asked your tyre dealer whether or not he can supply the MPSS 235/40R18?
When it comes to tyre width, you need to look up the specs. The number printed on the side does not tell the whole story. It just puts the tyre in a class of sizes, but tread width and section width can vary quite a bit - tread width can vary over an inch in some cases. It's late here, but I'll get back tomorrow and explain further. But if you can run 235/40R18 on 8" wide rims with an offset of 31mm. then an offset of 31,5mm and a rim width of 7.5" will put the edge of the tyre 3mm further in than yours. 2,5mm due to the narrower rim and 0,5mm for the increased offset.
Can you please explain further the difference in tread width and section width between different tires of the "same" size?
Fernando- Tires are just like shoes, not all are sized exactly the same even though they say they are the same size. If you go to TireRack's website and look in the specs section, you can compare different manufacturer's actual width and diameter of their tires. Easy to calculate the diameter of a tire from the spec, but the actual diameter will vary slightly, even for different versions of the same tire from the same manufacturer. Example is the 315/35 20 tires fitted to the F12 and 599 GTO. Considerable difference in width between the K1s fitted to the GTO and the K2s fitted to the F12, even though they are the same size.
Exactly. The MPSS for the front of the GTO is a 285/30R20 tyre. It has a tread width of 9.4". The MPSS front for the F12 is a 255/35R20 tyre. They are close to the same diameter, but the F12 tyre has a tread width of 10", As Terry said, you need to look up specs to know what's what. The rear tread width of the GTO tyre is 0.5" wider than the tyre of the F12 at 11.5" - the 295/35R20 tyre for the FF has a tread width of 12"! That's also why I don't calculate diameter, but go by spec - and that's also why I think the 225/45R18-275/40R18 setup is closer to stock than the 235 setup. Furthermore depending on the rim width, it can effect inflated tyre diameter by as much as 0.3" as well.
It's just an alloy wheel. No different than any other - it all depends on the person doing it. Anyone who know what they are doing and have the right tools can do it. I've seen more mishaps done at dealer shops than at good wheel and performance shops. Just because it's a Ferrari dealer does not mean they are any good at mounting tyres. Find a shop that balance to tyre to the rim so as little weight is needed and someone who is careful, that's the best you can do.
I just had the MPSS 235/40 & 275/40/18's put on modular wheels by a true "old school" tire shop in Chicago perfectly. If you look at this shop you wouldn't have them change the tire on a kids toy wagon! Why they don't even have a enclosed area to do the tire change! But they took their time, checked and rechecked the fitment of the different size for the front fender and now that I have a new pair of shoes I'm happier than a pig in sh#*!
Nice and what do you think about the PSS?? What did you have before?? 235/40 worked perfectly in the front no rubbing at all (inside and fenders)?
I had 10 year old MPSS OEM - 215/45/18 that were on the Mod wheels when I purchased them a few years ago. I have a pretty big lip to my driveway and there was some fender rubbing so I had the fender lips rolled awhile ago. I did go up my driveway with these and there wasn't any rubbing. I haven't had a chance to take it on the road yet but they do hold a lot better than the old ones.
Just to add another data point: I've put the following tires on my 360: Front: michelin sport cup 2 225/40/18 Rear: michelin pss 295/35/18 This combination of tires has about the same ratio of front/rear diameters as the oem tires. Ik know that according to the official specs the rears are a bit too wide for the OEM rear rims. I also know that some would probably like to shoot me for not putting the same type of tires on the fronts and rears I just wanted to create more grip overall and a bit less understeer (hence the sport cup 2 at the front). I couldn't be happier (so far). The handling and grip of the car are extremely good. I'm particularly happy with the grip of the fronts. Kindest regards, Chris
I stayed with stock for rear sizes, even on my wider rims (0.5 in plus 25 mm spacers) But up front I went with 235s on my 8.5 wide OZs plus 11 mm spacers. I have had good luck and better grip aside from one epic pot hole on my cross country trip to PA last month. A crevice looked a lot like asphalt in the late afternoon sun. At about 80 mph the wheel hopped on rebound (normal NOT sport setting) and tagged the lip. Either that or I caught it with the wheels turning right going over my driveway ramps a little too hot to save the clutch. I think it was the pot hole. I didn't look at that side of the car until a washed it the next day back in Boston. Full lock and body weight on the fenders shows good clearance still. I rolled back the little fold with a 2x4 no sweat. It was only about 1/2 and inch. You could only see it at wheel level.
I'll strongly advise anyone against doing this. Generally speaking, it's a very bad idea to mix tyre models, especially on a performance car. It can cause some very unpredictable handling characteristics. If you want more front end grip, go wider, don't mix tyre compounds and tread patterns. From a safety point, you'd be better off running 245/35R18 or 255/35R18 MPSS up front on wider rims and just have the fender lips rolled a bit if they catch. The much smaller diameter should however easily prevent this.
