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Rear tires: 245/45 x 16 vs. 245/50 x 16

Discussion in '308/328' started by dave80gtsi, Feb 6, 2008.

  1. dave80gtsi

    dave80gtsi Formula 3
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    Looking to buy a new set of tires soon, and had just about decided on the "upgrade" 225/50 front / 245/45 rear 16" combo.

    But another poster in another thread mentioned their substitution of the 245/50 size for the rear in lieu of the 245/45 size - the 50 being a bit taller in diameter.

    Would like to explore the pros / cons of the two size options before I pull the trigger. Anyone have any thoughts / opinions?

    Or, are the differences subtle enough not to matter that much, one way or the other?

    Cheers - DM
     
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  3. hardtop

    hardtop F1 World Champ

    Jan 31, 2002
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    245/50 is 20mm larger diameter than OEM. 245/45 is 3.5mm smaller diameter. Generally, the smaller tire will have less sidewall flex and more stable handling.

    Dave
     
  4. Qvb

    Qvb Formula 3
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    20mm is a huge difference. They are too tall. Your speedo will be off and your car will not look correct, they are too big
    in relation to the opening.
     
  5. dave80gtsi

    dave80gtsi Formula 3
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    Yeah, that's also exactly what I had originally thought, too, until someone, somewhere posted that the smaller 45 series looked too small for the fender opening - thus my original post question.

    Anyone have any pics of either the 245/45 or the 245/50 size to share?

    Thanks and Cheers - DM
     
  6. FourCam

    FourCam Formula Junior

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    #5 FourCam, Feb 8, 2008
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  8. dave80gtsi

    dave80gtsi Formula 3
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    Man, that's one serious look! Thanks, I love it!

    Any worries with tires rubbing - say, on the fronts at full lock?

    Thanks and Cheers - DM

    P.S. - Looks like Yokohama ES-100's, right? How do you like them?
     
  9. JazzyJay

    JazzyJay Formula Junior

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    #7 JazzyJay, Feb 8, 2008
    Last edited by a moderator: Sep 7, 2017
    I have Bridgestone Potenza 225-50-16 fronts and 245-45-16 rears (rear size on front, a little wider than stock on rear, same diameter). Here is a picture of my car with these tires, I like the looks. It was also a huge upgrade from the Pirellis (same size). These are VERY good at holding corners (even the ones you take a little too fast...)and have very little road noise. They are a little harder to turn than stock sizes at parking lot speeds, but not by much.
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  10. GrigioGuy

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  11. FourCam

    FourCam Formula Junior

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    NO rubbing issues on either end even at full lock. However, the front is still bottoming out occasionally, so I will soon add the steel undertray that has been discussed here before to save the underside of the front fiberglass. Handling is just ferocious--I love it! And the look, well it is subjective but I think it makes a 308 look like it should! Yes, the tires are ES-100's, reasonably cheap and with the tread pattern they shed water very nicely. I just wish I had done this years ago! As info, I added the driving lights that had been sitting in a box for about 20 years just to sort of emulate the GTO look which I have always found nicely aggressive in appearance, without getting too "far-out"...
     
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  13. MechanicMan

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    #10 MechanicMan, Jun 8, 2011
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  14. f1nxlife

    f1nxlife Formula Junior
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    #11 f1nxlife, Jun 8, 2011
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    245 45 17 rear 235 45 17 front,,,5/8 front billet spacers,,,,GO WITH P ZERO S....THERE IS NO SUBSTITUTE....PERIOD dont screw around,,,get the Perellis....ROSSO....they take some time to heat up....but the grip and sidewall strengh is insane.and unparralled.....!!! since you have 16 inch wheels,,the 50 series with fill in the fender well a little better,,,my car handles like a super kart,,,and i still have the stock suspension,,with 88k miles,,,,,80 mile an hour 4 wheel slides with exceptional feedback, and control...and grip......
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  15. jcinflorida

    jcinflorida Formula Junior

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    #12 jcinflorida, Jun 8, 2011
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  16. f1nxlife

    f1nxlife Formula Junior
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    why 45 s in back,,50 s would look better on all four legs ??,,why 225 to 245,,,could you have gone 235 in front on that rim,,,just wondering,,,i had 235 s on an RX 7 in front ,,same rim size i think,,,
     
  17. jcinflorida

    jcinflorida Formula Junior

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    As QVB pointed out, 50's would make the speedo off (read slower than actual) whereas with the 45's my speedo reads slightly fast. As for the fronts, maybe next time I will go with something wider for more stability. Wider is better, right? (that last statement does not apply to my GF though)
     
  18. f1nxlife

    f1nxlife Formula Junior
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    are the speedo s in 308 s mechanical ??? i believe the 328 s speedo s are electric and get a pick up from the tranny,,,maybe im wrong,,,but i see what you mean about the offsets...my speedo reads correct at all speeds,,,with the 17 inch wheels,,,
     
  19. f1nxlife

    f1nxlife Formula Junior
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    the gap shown in the photos seems abnormal...i dont believe my friends 85 QV has a gap that big,,,...
     
  20. f1nxlife

    f1nxlife Formula Junior
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    that 308 is really beautiful,,,man i love that color!!!,,i wish mine was that color,,,NICE<<!!!!!
     
  21. f1nxlife

    f1nxlife Formula Junior
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    that car is setup perfect.,....the best setup i have seen yet ., on a 308...
     
  22. hanknum

    hanknum Formula 3

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    I've been running 245/50 rears and 215/50 fronts on 16" rims for years. Great setup and looks right (lowered with QA-1s). Also, check to see the availability on both sizes. I'm pretty sure that 245/45's have very limited availability...even the 245/50's are scarce.

    FYI, with the 245/50's the speedo is spot on.

    I'll post some pix once I get around to renewing my subscription.
     
  23. CliffBeer

    CliffBeer Formula 3

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    50 series is the way to go. Speedo reads spot on as compared to my GPS.

    And, it takes a few revs off for highway cruising, which is appreciated.
     
  24. Paul_308

    Paul_308 Formula 3

    Mar 12, 2004
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    In 1982, Ferrari changed 308s from four 14" x 7 1/2" wheels to 16" x 7" front and 16" x 8" rear wheels. Factory recommended tires were 205-55 front and 225-50 rear through to 1989. They also changed from VR to ZR ratings midway during this time.

    Recommended tire pressure on 16" tires started with 33 psi all around to 33 front / 36 rear and 31psi front / 36 rear by 1989. The 14" tires were recommended with start psi of 28 front and 33 rear.

    Calculation - http://www.csgnetwork.com/tireinfo4calc.html
    Start the comparison with original 205/70 14" rear tires.
    Factory suggested rear 225/55 16" adds to circumference by 1.76% and the former 60mph now reads 61mph against the 14" set.

    However, going to the suggested 245/45mm rear tires reduces circumference by 2.47% and the speedo instead of 60mph now reads 58mph!
     
  25. dave80gtsi

    dave80gtsi Formula 3
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    #22 dave80gtsi, Jun 10, 2011
    Last edited by a moderator: Sep 7, 2017
    Since I started this old thread a couple of years ago, a closure update:

    I now have two (2) complete sets of 16” tires and wheels stored in my garage which I can easily swap for use with the 308, depending upon what I want to do:

    a) 205/55 front on 7” wide wheels, and 225/50 rear on 8” wide wheels. These wheels are the common QV aftermarket repo style, and the tires are Michelin Pilot Sports. This conventional 16” tire / wheel combination is the same as the later QV factory OEM set-up. I mount these tires / wheels whenever I do track days with my 308, for instance.

    b) 225/50 front on 7-1/2” wide wheels, and 245/50 rear on 8” wide wheels. These wheels are 16” aftermarket Gotti modular (period appropriate for the age of the car, which is an important detail for me) and the tires are Bridgestone Potenza RE750’s. These are my “street” tires, which I use mostly for day-to-day use.

    I decided to use the next-size-larger tires on the front Gotti wheels since these front wheels are 7-1/2” wide (as compared to the “conventional” QV’s 7” wide wheels), and I thought that the slightly larger tire width would better fit these + ½” wider front wheels. And, since these are intended for casual street use, I similarly went with the larger 245/50 rear tires as I wanted to fill out the rear wheel wells a bit more than with the QV OEM size.

    Subjectively, I think the car looks better with the larger Gotti tire size arrangement, but I’ll be the first to admit that these tire size / appearance differences are pretty subtle and are easily overlooked by most observers.

    I can detect no operational or driving differences between either set of tires relating strictly to their size. As I had suspected from the start, the size differences between these different tire widths and outer diameters are subtle enough that one can’t tell which set are on the car by simply driving one vs. the other back-to-back. Potential speedometer error, which has been occasionally mentioned by others, is really a non-issue in any case given the coarse resolution of the speedometer’s graphics

    Now, several years on, I believe that I made the right decisions concerning the sizes that I selected, and I feel as though I have the best of both worlds.

    Thanks - DM
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  26. Hans

    Hans F1 Veteran

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    ???

    I tried to get Pilot Sports here, but all tire shops told what the Michelin brochures also mentioned: Not being produced in 16" sizes...

    I'll ask again!!!

    Thanks,

    Hans

    (FWIW: I think you car looks magnificent with the QV's. Not so sure about the Gottis. Not that it matters what I think of course ;))
     
  27. Hans

    Hans F1 Veteran

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    From the michelin.fr corporate site:

    Pilot Sport:
    Largeur Hauteur Diamètre Charge Vitesse Spécification
    225 45 R 17 - ZR *
    225 40 R 18 88 Y *
    255 35 R 18 90 Y *
    275 35 R 18 87 ZR(Y) ZP
    345 30 R 19 98 ZR(Y) ZP
    (and that's all)

    Pilot Sport 3:
    Largeur Hauteur Diamètre Charge Vitesse Spécification

    195 45 R 16 84 V
    205 55 R 16 91 V
    205 55 R 16 91 W
    205 50 R 16 87 V
    205 45 R 16 83 V
    205 45 R 16 87 W
    215 45 R 16 90 V AO

    205 50 R 17 93 W
    205 45 R 17 88 W
    205 40 R 17 84 W
    225 45 R 17 91 Y
    225 45 R 17 94 W XL
    225 45 R 17 94 Y
    235 45 R 17 97 Y XL
    245 45 R 17 99 Y XL
    245 40 R 17 91 Y
    225 45 R 18 91 V
    225 40 R 18 92 W XL
    225 40 R 18 92 ZR(Y) XL
    235 40 R 18 95 W
    235 40 R 18 95 ZR(Y) XL
    245 40 R 18 97 Y AO
    245 40 R 18 97 ZR(Y) XL
    255 40 R 18 99 ZR(Y) XL | MO1
    255 35 R 18 94 Y XL
    265 35 R 18 97 ZR(Y) XL
    275 35 R 18 99 ZR(Y) XL
    285 35 R 18 101 ZR(Y) XL | MO1
    245 40 R 19 98 ZR(Y) XL
    255 40 R 19 100 Y XL
    255 35 R 19 96 Y XL | AO


    Pilot Super sport:
    Largeur Hauteur Diamètre Charge Vitesse Spécification
    225 45 R 18 95 ZR(Y)
    245 45 R 18 100 ZR(Y)
    245 40 R 18 97 ZR(Y)
    265 40 R 18 101 ZR(Y)
    225 40 R 19 93 ZR(Y)
    225 35 R 19 88 ZR(Y)
    235 35 R 19 91 ZR(Y)
    245 35 R 19 93 ZR(Y)
    255 35 R 19 96 ZR(Y)
    265 35 R 19 98 ZR(Y)
    265 30 R 19 93 ZR(Y)
    275 35 R 19 100 ZR(Y)
    275 30 R 19 96 ZR(Y)
    295 30 R 19 100 ZR(Y)
    305 30 R 19 102 ZR(Y)
    235 35 R 20 92 ZR(Y) K1
    255 35 R 20 - ZR
    275 35 R 20 - ZR
    285 30 R 20 - ZR
    285 30 R 20 99 ZR(Y) K1
    285 25 R 20 93 ZR(Y)
    295 35 R 20 101 ZR(Y) K1
    295 25 R 20 95 ZR(Y)
    315 35 R 20 110 ZR(Y) K1
    345 30 R 20 106 ZR(Y)
    255 30 R 21 93 ZR(Y)
    265 30 R 21 - ZR
    295 30 R 21 - ZR
    295 25 R 21 96 ZR(Y)
    235 30 R 22 - ZR
    265 30 R 22 - ZR

    In other words: NLA.... :(
     
  28. dave80gtsi

    dave80gtsi Formula 3
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    #25 dave80gtsi, Jun 10, 2011
    Last edited by a moderator: Sep 7, 2017
    I bought my Michelin Pilot Sports about 5 years ago, and I think they are now out of production. See old pictures below.

    No probs about the Gotti wheels, I've had an equal number of people who like them as those who don't, so I am use to the "love it or hate it" reaction!
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