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Is 4.4 seconds vs 5.6 seconds alone worth $10k?

Discussion in 'Model S: Driving Dynamics' started by Jrhodesmd, Mar 29, 2012.

  1. rlawson4

    rlawson4 Member

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    My question about the performance S vs. Regular S has to do with comfort. I ma in my car all day. I don't know much about wheels. Would I get more comfort and a better ride out of the 21" or 19" wheels? Also, do the 19" inch wheels have a longer life. If someone could explain this to me my decision will be made. Thanks in advance
     
  2. de704

    de704 XP268

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    Your bumping up against to limit of street tires.

    I rather see a roadster built on a Model S inspired flat battery chassis with a 0 - 60 in 3.5 seconds with a range of 600 miles per charge that a 6 foot 7 person (Me) can fit into comfortably.
     
  3. jerry33

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

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    The 19" wheels will be more comfortable because they have more sidewall and they will have much longer life--perhaps double or more.

    The 21" wheels will be faster off the line, primarily because of the stickier tread compound.

    The shorter-wider contact patch of the 21" tires will deliver more g-force.

    Both will have the same contact patch area if run at the same pressure because contact patch area mostly depends upon the air pressure in the tires (and a very small amount on sidewall stiffness).

    The 19" tires will most likely be better in the rain because the tread width is narrower. In this case I say most likely because sometimes tread compound more than makes up for the increased width.

    The 21" tires will become very hard, and lose traction, when the temperature drops.
     
  4. onlinespending

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    and i thought i had it bad at 6'5"! personally I'd rather they not build another Roadster. for a small company like Tesla, it simply doesn't make sense. it's not the type of car with mass appeal. there's a reason you see way more 3-series BMWs on the road versus Z3s. it made sense for Tesla to make the original Roadster, since they could borrow the chassis from Lotus and keep the weight down. but now I'd like to see them focus on sedans and crossover vehicles. it just makes the most business sense for a company that's going to produce a limited number of models. it'd be a costly mistake to divert their attention away from this and focus on another roadster that will not approach the sales volumes of the Model S or another sedan.

    But if they wanted to, I guess it'd make more sense to come up with a coupe with hard-top convertible as opposed to a pure roadster.
     
  5. de704

    de704 XP268

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    That's one of the main reasons why I switched to the Model X. And when I heard you get close to the same stability & performance as Model S (and more time to save) It was a no-brainier for me.
     
  6. rlawson4

    rlawson4 Member

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    Thanks. 19" for me. I need a better ride and safety is important as well. I appreciate the response.
     
  7. PV4EV

    PV4EV Member

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    Unless I'm missing something here … surely a 19" wheel is going to give marginally better acceleration, and reduce the negative effects of unsprung weight by being a smaller diameter and lighter in weight, and be marginally more responsive to directional input, and replacement tyres are going to be easier to find than some very expensive 21" whoppers.

    I vote for 19" wheels.
     
  8. ElSupreme

    ElSupreme Model S 03182

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    I wouldn't assume/conclude that the tires on the 19" wheels are safer than the ones on the 21" wheels.

    I am also not pretty sure both the 21" and 19" wheels are coming with equal width tires.

    I think the only thing you can assume as far as size is concerned is 19" = softer ride and less cost, 21" = harsher ride and more cost.

    As far as performance versus all-season you can assume is performance = much better grip and shorter life, all-season = less grip and much better life.
     
  9. ElSupreme

    ElSupreme Model S 03182

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    Well the overall tire diameter is the 'same' for both cars. And in general wheels weigh less than tires. So going with a large wheel and smaller tire you may actually get overall weight savings. That being said you move the rim portion of the wheel further from the axis and increase the moment of inertia ... so in general I think it is a wash as far as acceleration goes. But talking about unsprung weight I think you would get less overall weight with the larger rims.
     
  10. Doug_G

    Doug_G Lead Moderator

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    Yes, I'm assuming AWD.
     
  11. Sig698

    Sig698 Model S Sig Perf #698

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    In addition to the above, acceleration and braking performance will likely be improved due to the increased grip of the stickier tires. Directional input will without a doubt be more direct with the 21" wheels due to the shorter and stiffer sidewall of the tires.
     
  12. rlawson4

    rlawson4 Member

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    We need a thread on the advantages and disadvatages of 19" vs 21"

    I am lost again. I am sorry but I don't care about the appearance. I think both look fine to me. I need to know the pros and cons of each wheel completely. That way I can make a decision. I am sorry in advance to the experts if this sounds obtuse. However, I have had 8 new cars in my life and have never made a wheel tire decision. I took the wheels that came with the car on the lot that I saw that day. Thanks.
     
  13. Sig698

    Sig698 Model S Sig Perf #698

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    #73 Sig698, Mar 30, 2012
    Last edited: Mar 30, 2012
    Start one and I'll be happy to chime in! Long story short;

    21": better all around performance
    19": better comfort and longevity.
     
  14. onlinespending

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    That's assuming you're using the stock tires. Of course you could use performance tires on the 19" wheels that'd have similar issues of longevity due to the softer rubber. But in general I agree.
     
  15. dadaleus

    dadaleus 4GETOIL P85#S70,FdrX,S85D

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    And vice versa? Are there all season tires that would fit the 21" rims?

    I'm also concerned about if the 21" wheels will be a bigger issue for using tire cables/chains in the snow. I haven't been able to get a confirmation from Tesla as to whether they will allow them on either tire size. Since this will be my only car that would be a big problem for my regular ski trips.
     
  16. Teslawisher

    Teslawisher Member

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    While the wheels are different diameter, the overall wheel/tire combination diameter is going to be fairly close to the same for the 19" wheels (larger sidewall) and 21" wheels (small sidewall). So, in regards to diameter, as long as you have chains to fit, there shouldn't be a problem between each. You will need to consider wheel/tire WIDTH though. There will more than likely be a difference there.

    You can get 21" all-season tires, but they are harder to come by than those for the 19". Check tirerack.com or places like that to get a good general idea of what's out there at what price.

    Sorry for keeping us off-topic. Maybe a new thread would be best.
     
  17. efusco

    efusco Moderator - Model S & X forums

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    checking prices on those tires the 19" are markedly less expensive, it seems.
     
  18. richkae

    richkae VIN587

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    I disagree. Put the same tires on either wheel and you are unlikely to be able to tell a difference.
    The shorter stiffer sidewall on the 21s will provide a tiny cornering benefit that would take a professional driver to detect.
    The only real advantage of the 21s is cosmetic.
     
  19. ckessel

    ckessel Active Member

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    Was there anything definitive on the impact of 19" tires on acceleration? I'm ok with losing a little (say, .2) with 19" tires, but I wouldn't want to lose a bunch or it'd make it pointless to get a Perf with 19" tires even though Tesla allows it.
     
  20. ggr

    ggr Roadster R80 537, SigS P85 29, M3P 80k

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    But as you just pointed out, the tire is both heavier and further out, so I think it's actually a net win for moment of inertia too.
     

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