hey guys, been reading around the forum was wondering what are some tire size i can run wider than stock 215/45/18 + 275/40/18 on the oem 18 ? hoping to get a set of either hankook rs-3, dunlop starspecs, bridgestone re-11, or advan ad08 but more of those tires have minimum 225 up front i dont want to upset the traction control, so please give me some suggestions thank you
Those are sticky tires, in such case the RS3 has the highest dry grip (a little loud but great grip). I prefer the RE-11 over the RS3 for a daily driven car, RS3 is bad in the rain and it is a short lasting tire. RE-11 was evolved from the RE-01R, and RE-01R is superior in all performance parameters to the RE-050A. RE050A is a OEM tire fitted to many Ferraris. If you go RS3: 235/40R18 and 285/35R18 they fit the stock wheels. If you go RE11: 225/45R18 and 275/40R18. No TC or ABS problems with these sizes. With the RS3 the car will run about 8mm lower. No need to change the alignment, under the assumption that the car is aligned, but most owners have never aligned these cars and they think the car drive on rails (until they get the chance to drive a properly aligned car). Use 4mm total toe-in at the rear, (0.25 degrees per rear corner), to eliminate the tail happy 360/Stradale/Spider at the limits.
thank you so much for the information i just got my ferrari 360, and also just picked up a set of oem 18 as it had chrome 20s from the previous owner... anyways yea i was thinking of the rs-3 and re11 since this is my weekend car, i have a m3 for track which im using starspecs on so i just wanted to make sure on tire sizes so i dont offset the cars stability too much once again, thanks for the great response and information edit: also was looking at the dunlop starspecs is it ok to run 225/45/18 with 275/35/18 ? or the available sizes that the dunlop starspecs come in?
-1.5 degrees front and -2.0 degrees rear for a car mostly driven on the streets (regardless of F430, 360, Scuderia, 16M). For track use, the front need more negative camber that rear, and -3.5 front -2.5 is a good start. Tune from there according to tires, springs, tracks, height, rake. Rake at 20mm is just right, either 360, F430, 360CS, Scuderia/16M.
For your info, I switched from 215/45/18 to 225/45/18 and found I was snagging the fenders and had to roll them, no problem since. I have stock ride height. As regards using 275/35/18 with 225/45/18 you may have an issue with ABS / ASR - I cannot say. Standard setup has a diameter which is 4.1% greater at rear than at front. Your query setup would produce a rear tyre diameter which would be 1.5% less than the front. That's a change of 5.6% from stock which is likely to be outside of the acceptable range for the computer.
No issues with ABS/ASR. When using different tire sizes from stock, the % variation must be used based on the stock front/rear tire diameters as a baseline. It is not the overall diameter difference to be measured, but the ratio between front/rear diameters for stock sizes and new sizes. As long as the new ratio stays within 4% of the stock ratio, ABS/ASR will work just fine. This tolerance is built into most cars these days (the actual tolerance is 5%). So being 1.5% within stock ratio of diameters front/rear is way below the 4% I mentioned above. These rules apply to 360/F430/458, 996/986 and 997/997 Porsches as far as I have tested.
Hi Rad, not picking an argument with you here, just trying to enhance my knowledge on the subject. I would have thought that the 360's computers would be programmed to see a tyre diameter of 651mm & 677mm (Front/Rear) as bang-on. Effectively that the 360 ECU sees those numbers, rear-larger-than-front by 4.1% as perfect. The combination proposed above would give 660mm & 650mm, whereby rear is now 1.5% smaller than front. In total that is a variance of 5.6% from standard. My understanding to-date has been that it generally safe to stray a maximum of 5% form standard spec. and as such, the proposed 225/45 and 275/35 would appear to be outside of that range. Are you saying that you feel that it's acceptable to vary the front to rear ratio by as much as 5% to -5% (i.e. a range spread of a full 10%)?
Looking for just a bit more High tyre PROFILE in order to protect Car and weels from bad road quality .... Can I use for my 360 front 215/50/18 instead of the OEM 215/45/18 and (3.23% dif in diameter - 672 mm instead of 651 mm) rear 275/45/18 instead of the OEM 275/40/18 ??? (4,14% dif in diameter - 705 mm instead of 677 mm) Will it feet to my fenders with out any problem? Ps as you can understand ... max racing attitude of the Car is not my priority... )
The proposed sizes have very close ratio to OEM so there certainly should be no issues with the ASR or ABS. The tyre wall would be approx 11mm higher on the front and it might give clearance issues on the fender which, if an issue, could probably be resolved with a little gentle rolling of the lips on the fenders. I'd be very surprised if you had any clearance problems at the rear. Not a common modification so you'll probably have to suck and see as you're unlikely to get user feedback here.
Hi, I have just bought my F360 and the previous owner put the following on standard rims: Front: Michelin PS2 225-40-18 Rear: Michelin PS2 295-35-18 Would there be TC/ABS problems? Many thanks in advance.
Johnny- If you are not seeing any problems, I would not worry about it. To calculate yourself, go to TireRack and look up the tires fitted and go to the spec section, which will show you the diameter of each of the tires. Then simply subtract the front diameter from the rear diameter. Divide the result by the front tire diameter and see if it is close to the OEM difference of around 4.1% noted by Greg above. If you want to calculate the tire diameters and do the math it works like this: (225x0.40x2)/25.4=7.09"+18"=25.09": (295x0.35x2)/25.4=8.13"+18"=26.13" 26.13"-25.09"=1.04" 1.04"/25.09"=4.15%, almost exactly the same as OEM so no sweat. ABS does not care how big the tires are, only that the front to rear differential is close to the OEM +4.1%.
I have had a growing problem with my ASR (cuts the engine - not brakes) kicking in when it shouldn't (dry roads, straight line, not booting it). The problem is usually after the car is hot, and after it has been left for a short while (but this may be a red herring) and revving over 4k. Sport mode fixes it. Stock 360 Spider. I have two sets of wheels and tyres, one for road (Michellin) and one for track (Trofeos), all on 18" wheels. I have looked at your calcs above to see if it is a tyre size issue, but I think I am OK (road tyres): Front (215x0.40x2)/25.4 = 6.77" + 18" = 24.77" Rear (295x.30x2)/25.4 = 6.97" = 18" =24.97" Difference front/back is 0.2"/24.77" (x100) = 0.8% Track tyres are front (235/40/18) and rear (295/30/18) = 1.6% Does anyone know how the 'puter works out the percentage difference between wheels and if it is adjustable? These things only ever get worse. Any help or ideas much appreciated. OP - the above widths fit fine with no snagging on the bodywork. roger
We hear about 5% being the level of disruption the systems will accept. One would have thought that if there is a tolerance of 5% built in to the system that it would be +/- 5% and that it would be relative to the OEM settings. Thus stock sizes being front smaller than rear 4% one would have thought that the differential that the system would be comfortable with would be anywhere from -1% to + 9%. Your track tyres would appear to be just outside of the sweet spot if the above assumptions are accurate. You're sitting on -1.6% (I make it -1.7% actually) versus OEM of 4.1% = differential from OEM of 5.8%. Do you only have the problem with the track tyres or both? I've never seen anyone "nail their colours to the mast" on this issue though. Maybe the 5% operates from -5% to +5% and as such our OEM settings are just within the tolerance and a little variance (in the wrong direction) will bring you out of tolerance. You could also have a wheel speed sensor causing intermittent problems!
Thanks for this. I will in the next few weeks drive round with my indy mechanic and with his diagnostics plugged in to see of we can nail it. Will let you know the outcome. What's the betting the ASR behaves perfectly?
I run 225/40/18 (?) Michelin Pilot Sport A/S 3's up front no problem. If you get a couple 275's for the rear I have 4 225's with under 500 miles on them that came off my BMW trade in, sell two for 1/2 of new including shipping if you are in Continental US..
Hey Terry! So using your formula for the math gives me this: 360 OEM: Front 25.62 Rear 26.66 Equals 1.04 inch different So if I go with Hoosier R6 tires at: Front 245/35/18 at 24.75" Rear 295/30/18 at 24.97" leaves only .22 " so .22 divided by 24.75 is only .01% right? So no ASR issues I assume but wondering if I can get away with the tires on my lowered 360. I think it is dropped a half inch or so.... Any help is always appreciated. thanks
Shows these tires are .87" lower in front and 1.69" lower in rear. My car is lowered around an inch I think and not so sure on these working.....might be driving a magic carpet skimming the ground...not really interested in raising the car ;(
Well, I have run around a few circles on this (pun??). I tried different mixes of the tyres I have (see above for track vs road). I can report that the ASR is pretty sensitive to the difference in ratio between diameters front and back. The prettiest result was track tyre rear and road tyre front - lit up the dash like a Christmas tree. The diagnostic reports all is well with the system, it is the diameters that is causing the problem. I think Ferrari Dublin (above) is right about the tolerance. Mess with diameters at your peril. I am reverting to the stock sizes for the road. For the track, the ASR is either on sport or off. Or of course, I could still have a bug in the ASR system. But changing all four hubs to find out is a bit radical. Hey ho,
Hi, I want to change the tires of my 360 and would like to stick to the factory size (215/45/18, 275/40/18). The obvious problem is that these sizes are very uncommon. Any suggestion of what to put on, please? I don't do track day and no snow in my region. Thanks in advance. John
John is right, there are not a lot of combos from a manufacturer that fit. Bridgestones get a good report from many. I went with a set on the rear, but too early to tell.
?? Tirerack shows 10 different Ultra Performance summer and All season tire sets in these sizes. 3 Bridgestones - RE760, RE1, S-02 A 2 BFGs - G Force Comp 2 A/S, Sport Comp-2 Hankook V12 evo 2 Pirelli P Zero Conti Extreme Contact DWS General G-Max AS-03 Michelin Pilot Spot A/S 3
