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Wider rear rims?

Discussion in 'Model S: Driving Dynamics' started by Shurhold, Apr 3, 2013.

  1. Shurhold

    Shurhold Model S - P#15,582

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    Reading the new tesla model s pages I found a strange reference. On the features page in the performance option section:

    "Performance Plus Package
    Performance Plus upgrades an already impressive handling car by stiffening key suspension linkages and tuning dampers to increase lateral stiffness without compromising ride. 21" wheels with wider rear rims and Michelin Pilot Sport SP2 tires channel these improvements to the road. The result is nothing short of amazing-light, responsive steering with minimal body roll. It's a performance junkie's perfect daily driver."

    It states : 21" wheels with wider rear rims.....

    I checked my car and the front ant rear are the same. Are they changing this or is this a typo?
     
  2. Johan

    Johan Took a TSLA bear test. Came back negative.

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    You don't have the Performance plus package". It is a new option as of yesterday. Only Elon has it thus far.
     
  3. AC1K

    AC1K Member

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    staggered tires are pretty common for performance sport sedans, however the traction control system has to be calibrated, the rear tires turn slower than the front.

    upsides: you get better traction
    downsides: lose millage, tires are much more expensive, the SP2s they put on are good but they wear out fast, the conti's have a higher rating on tirerack than the sp2s,

    i personally wont get it, how fast do you really need to go around a corner? if you wanted a cornering car you need something light and nimble, not a 4700lbs car.
     
  4. derekt75

    derekt75 Member

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    My car frequently skids a bit on launches (with the yellow light flashing), and I thought the wider tires would help with that, no?
     
  5. rcc

    rcc Model S 85KW, VIN #2236

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    I think wider in this case means wider left to right as opposed to larger diameter wheel. Tire sizes are X/Y (225/45, for example). Wider wheels/tires means X gets larger. Larger diameter means lower profile tires which makes Y get smaller.

    So yes, I expect the Performance Plus package will come with 21" rear wheels and tires that are wider than the on the current Performance package. Not the same wheels in other words. This lines up with the earlier Edmunds review where they got a car that had tires and suspension from a "proposed Sports package".

    The wider rear tire gives you a larger tire contact patch which should result in better traction on launch and better traction when cornering, especially if you're applying power in the corner to help you hold the line.
     
  6. Rodolfo Paiz

    Rodolfo Paiz P85 "Plug and Play"

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    I look at it differently. I don't want a "cornering car", I want a Model S. But having made that choice, I'd like to get the best possible cornering and stopping ability from it that I can. Turning and stopping are much more important to me that accelerating, since those keep me in one piece. :)
     
  7. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    I'd like the rear camber fixed up a bit to prolong my tires a bit. :)
     
  8. bellwilliam

    bellwilliam Member

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    wider rear is to dumb the car down for more understeer......
    unless you think the car is tail happy right now, there is no need for a wider rear. you want wider all the way around.
     
  9. Zextraterrestrial

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    car is a little 'tail happy' after you wear the 245s out a little
     
  10. Kaivball

    Kaivball Member

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    Wider tires in the rear doesn't necessarily change the rolling diameter.
    Wider in the rear does not cause them to roll slower in the rear.

    I am running 235 F and 295 R in my sports car but they are both within less than one tenth of an inch in rolling diameter.
     
  11. Kaivball

    Kaivball Member

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    It is very tail happy right now. Under hard acceleration coming out of the turn the power overwhelms the rear tires. Going to a 265 or even 285 will dramatically improve the contact patch.
     
  12. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    No it won't. The contact patch is controlled almost entirely by the air pressure and load. If you have a 1200 lb load and put in 40 psi (example numbers only for easy calculation) the contact patch will be 30 sq. in regardless of tire size. Now if you run the wider tires at a lower pressure that will increase the contact patch, but just wideness by itself won't do it. What the wider tire will do is change the shape of the contact patch--it will be shorter and wider. So you will give up traction for g-force all things being equal (which they usually aren't).
     
  13. Kaivball

    Kaivball Member

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    #13 Kaivball, Apr 8, 2013
    Last edited: Apr 8, 2013
    Very interesting reading on this subject...

    :)

    Fact or Fiction? Tire contact patch and air pressure.
     
  14. bellwilliam

    bellwilliam Member

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    if that's the case (while others are right about no more contact patch, you are right about the car being able to put the power down better, less wheel spin), you are still better off with wider 265 (or 285) all around. or steady state handling will be horrible understeer.
     
  15. Kaivball

    Kaivball Member

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    True, without adjustments you'll introduce understeer. But like I said, on my sports car I am running 235 and 295...
    So it's possible.

    My BMW 650 ran 245 and 275. Made rotating directional tires difficult, lol.
     
  16. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Bear in mind that there will be more than just width and aspect ratio difference. There will also be tread compound, belt construction, and bead differences as well between the various sizes. All these have an effect on handling. However, regardless of the pluses or minuses of the tire, only having the proper rim width and suspension tuning will allow the tires to perform optimally.
     

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