Hi all, I may be getting original 16" convex wheels soon and am researching tire choices. Apparently, the original tire sizes are 205/55R16 front and 225/55R16 rear. This seems interesting as it makes the front tire diameter smaller than the rear. The 308 and 328, for example, have 205/55R16 front and 225/50R16 rear, making both front and rear diameters close to identical. What was Ferrari's rationale for doing this? Lower rpm's on the highway, or something to do with handling as well? On another note, is anyone running wider tire widths than normal on the original rims? I am slightly considering 215/55R16 up front and 235/50R16 in the back. I used to "plus size" the tires in my other cars in the past, but the benefits are debatable. However, these sizes would equalize the diameters between the fronts and the rears, just slightly lowering highway efficiency. 205/60R16's unfortunately isn't available on the good tires, otherwise I'd consider that on the front and the original size on the rear. Maybe I'm over-analyzing it all! Thanks, Leo BTW, this site has a fantastic tire size calculator: http://www.miata.net/garage/tirecalc.html I hope it's OK to post external links.
When I was still running the factory rims (now in storage) I went to a 225/45 front & 245/45 out back (dropped the aspect ratio accordingly). I like it a lot but it was just a baby step towards the performance of the even larger set I have now.
Hi Leo, Just a note regarding those tire width and diameter questions. The Mondial t does "absolutely" sit in a slightly aggressive lower front stance due to the factory larger diameter rears. If you go to rear 50s', do maintain that roughly .9" difference over the fronts. As for the fronts, if you go wider, you may experience a slight "wandering" feeling. I've also found that there can be quite a difference between the measurement specs. of equal sized tires from different manufacturers. When I compared tire specs, I found the F1/GS-D3 to be significantly "meatier" than most other tires - so, Goodyear, it was. Some shops still have them. Good luck, Hank Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Thanks guys. I'm now leaning towards 205/55R16 in the front and 235/50R16 in the back... It would lessen the difference between the two diameters but not completely. Don't know why but I have this temptation to resist going full-out stock. Leo
HI I went with Yokohama s drive in the original tyre specs as per the door sticker. I am very happy with them They are quiet, give great grip and are a good soft compound.
Leo- The ABS system is set up for the factory differential in tire sizes, in this case 205/55 16 is 24.88" in diameter and 225/55 is 25.74" , a difference of +3.46%. If you deviate from that differential by around 5%, the ABS may not operate properly. Your 215/55 16 diameter would be 25.31" and 235/60 16 would be 27.10", a difference of +7.07%. Difference from stock is 7.07%-3.46%=3.61%, well under 5%, so they should work fine. Always good to make that comparison and save yourself a brake warning light. Incidentally, the math is so simple on tire diameter, it is easily done with a hand calculator in a few seconds. [(205x0.55x2)/25.4]+16=24.88" If you look in the OM, however, they quote a different circumference for each tire type (diameter x 3.1416), so not always spot on in earlier tires. More accurate in later tire types. You can look up individual tire diameters at TireRack.com under specs to make sure. Taz Terry Phillips
Once again: in a given tire size, the diameter will be fairly consistent between brands. But in those same tire sizes, I believe you'll find some pretty dramatic differences in tread width. This will affect the overall look of the wheel/tire combination, I would think even more than a diameter change. That was one of the reasons I chose the F1/GS-D3 for Rachel - and those a stock sizes. Cheers, Hank
Thanks again for the advice. I was close to choosing Continental ExtremeContact DW's, but now have edged towards Yokohama S.Drives, in stock sizes. The info regarding tread width difference among manufacturers was very interesting. Reading through various boards, the DW's are perceived to have a relatively smaller width. The S.Drives on the other hand are pretty "meaty". According to Tire Rack, they're even slightly wider than Goodyear GS-D3's for the same size, and as Hank's Goodyears fit and look good, so the S.Drives should as well. Doesn't hurt that the S.Drives are cheaper, and Frari recommends them! I would like to have more options, but the rear 225/55 16 size really limits choices. Lots of options in 225/50 16, and funnily, with the exception of Toyo Proxes T1R, none in 235/50 16! Leo
Hi, I had my first opportunity to drive with the s drives in torrential rain on tuesday, I was very impressed, so much so that I felt relaxed. With my old eagles I was lucky to feel comfortable keeping up with the normal traffic with these I was not conscious of any aquaplaning and the grip felt just like a dry road... almost. I am happy with mine and have now done about 300kl on them so they have settled in. I do notice a little side wall movement ie they are probably not as firm in side wall roll as other tyres I have had but still grip is excellent, this could also be because the eagles, previous tyre, at the rear had a 50 profile rather than the recommended 55, the lower the profile the less sidewall roll.
I've been following the conversation on the Mondial tire sizes as i am about to buy new tires for my 90' t cabrio. I have always wanted to go a bit more aggressive. It seems that the best way to go without going overboard would be the Yokahama S drives 225/50 front and 245/45 rear on stock 16" rims. Any other suggestions? Thanks John
I looked at Toyo as well but the only solution was the 55 front and 50 rear so the rolling diametres were altered meaning your speedo may be more inaccurate.
I have Superformance 16" rims on my QV with the following tires: Toyo Proxes T1R 205/55R16 (front) Toyo Proxes T1R 225/55R16 (rear) For information: The original TRX (with 240 tires) total wheel weight is 20.5 kg, its SLR 309 mm at 35 P.S.I.. The 16" SP/Toyo total wheel weight with 205 tire is 19.7 kg (front) and 21.0 kg in the rear with the 225 tire. The SLR for the Toyo 225/55 rear tire is 310 mm at 35 P.S.I., so the speedo remains accurate. The Toyo tires are quiet, offer good grip even in the wet, give you some warning before breaking loose and are correctly priced.
I have to replace the F-1/GS-D3's on my car soon (18K miles!) and will be going with the stock size. The Yoko's sound good.
No Bridgestone fans here? I still like my Potenza S-04's, and was looking to go to Potenza RE-11's (which may be more tire than the car needs, but look badass)
Hey guys. Sorry for being gone so long. The car has been in the garage for an extended period, getting some bugs in the engine fixed. I finally decided to buy a set of Continental ExtremeContact D/W in the stock sizes, and bought Hank's set of original wheels, but have not been able to put them on yet. When I do, I'll post some pictures so we can see how the tires looks in relation to the wheels and body. Leo
Hi Leo, I can't wait to see pictures of your Mondi with her new wheels and tires. You'll surely be in contention for that Platinum award at the next car show. Your Mondial is a winner !! Cheers, Hank
Still happy with my Yokohama S drives, good grip also in the wet, they remind me of my pirelli corsas in that there is the usual black tyre dust on the rear bottom guards behind the wheel when you get home after a spirited drive... means they are working.
Hank, your wheels turned out wonderfully! You were right when you said I couldn't possibly be disappointed in them - they look brand new and are in pristine condition. My tire guy was stunned by their condition for being 22 years old. The original-size Continental ExtremeContact D/W's are working out nicely so far. I love the electronic suspension - very comfortable ride in "soft", good balance in "normal", and firm but not jarring in "hard". Switching from the 18" to 16" was one of the best decisions I made all year. Leo Image Unavailable, Please Login
Hi Leo, Isn't that electronic suspension rocker switch, a total gas??!! Wait till you hit a bit of roadway with those annoying seam bumps - - just rocker to "soft" - - and they're GONE! I like to stay in mid position while in town as it helps to prevent bottoming out in surprise dips. "Hard" is awesome in the twisties Needless to say, I'm very happy that you're pleased with your new wheels and caps. Thanks for the confirmation Oh, and BTW..........your Mondi is simply beautiful!! Cheers, Hank
Hi Hank just noticed it was your t cabrio in the previous post nice looking car and your tyres look similar in size and profile tyre to the Yokohama s drives that I have on mine. They are very quiet compared to the old ones. Nice car I would like to drive a cabrio.
Hi Tony, Well, now that the GS-D3 tires are almost a thing of the past, though I was able to outfit my Speedline 17s" with a full set, the next set will be from a new supplier. I'll probably look into those Yokos that you're so happy with Cheers, Hank
