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Fitting 19" wheels to my P85+ - is this possible?

Discussion in 'Model S: Driving Dynamics' started by Mike_C, Mar 21, 2016.

  1. Mike_C

    Mike_C Member

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    So my P85+ (with 21” staggered wheel setup) has gone into the dealer for some warranty work, and I have a standard 85 loaner with 19” wheels; both cars ride on air suspension. Naturally, I’ve noticed some differences and it’s got me thinking…


    My car feels more planted at speed, and I put this down largely to the different suspension settings and hardware that the ‘+’ pack gives it. However, another thing I have noticed is how much more ‘chuckable’ the loan car feels, and I think this down to the smaller wheels; whereas my car may have more outright grip on a smooth surface, the higher (and thus more flexible) sidewalls seem to offer more grip on our twisty, broken-tarmac roads over here in the UK. Certainly I’m a lot more confident chucking this into a fast bumpy bend than I am my car!


    I am therefore considering getting a set of the 19” Cyclones (or better still, the new standard 19” ‘Slipstream) for my car, as I feel this would be the best setup overall in terms of handling, comfort, etc. I would probably keep my wheels for resale, not sure.


    My question is, has anyone fitted 19” wheels to their P85+, and will/do these work OK with the ‘+’ suspension pack? Noting that my wheels are a staggered setup (245 front, 265 rear) and the 19’s only come in standard fitment. I assume this is no different to fitting 19” winter wheels/tyres to a P85+, though?


    Let me know your thoughts!


    Thanks, Mike
     
  2. Gizmotoy

    Gizmotoy Active Member

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    There's been some discussion of this in the past you might be able to find with a search.

    The main thinking is that, yes, 19"s will fit, but you should consider changes cautiously. You might consider fitting the 19"s with grippy tires. The main reason most believe Tesla used the staggered setup for some P85+ is to provide some margin for understeer. With thinner rear tires, the car may be prone to oversteer at the limit, which most find more difficult to control. As the P85+ suspension evolved, the staggered setup became unnecessary to provide that additional margin and was eventually eliminated.

    It's probably hard to say for sure where your vehicle came on that spectrum unless it was delivered during the transition period where both fitmets were shipping simultaneously. A variety of P85+ owners switched to 19"s, so the change is not unheard of.

    The actual contact patch of the 19"s and 21"s are nearly identical (the 19"s are actually slightly larger, in fact), it's just all that additional sidewall that leads to the very different turn-in feel. Your loaner also had all-season tires fitted, which provide less grip, and also contribute substantially to overall handling feel.

    Hopefully one of our P85+ owners who have made the switch chime in for you.
     
  3. Dithermaster

    Dithermaster Member

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    I have a P85+ with staggered factory 21" and purchased a set of factory 19" with all-season tires for winter driving (some folks do the same thing with snow tires but I hate the swishy feel of snow tires so I went with all-seasons).

    The staggered 21" can definitely be switched out with 19" but you must have the Smart Air Suspension rear height adjusted when you do this, which means a trip to the Service Center.
     
  4. AWDtsla

    AWDtsla Active Member

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    Must??? Why is it a "must" and which way do they adjust it?
     
  5. Johan

    Johan Took a TSLA bear test. Came back negative.

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    It is my firm belief that you can go ahead and put 19" wheels on a P85+ car without any adjustments. You can also put on 20" wheels or non-staggered 21" or 22" wheels as well.

    Smaller wheels (19") should be fitted with thicker tires so that the wheel+tire circumference is in practice unchanged.
     
  6. Dithermaster

    Dithermaster Member

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    Well, that's what they told me when I got the car. Since they're going to be doing my summer/winter tire swaps I'll just have them do it when they have the car.

    My understanding was that the wider rear tires are also taller, and so the adjustment is required.
     
  7. mgboyes

    mgboyes Member

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    The staggered rears are taller than the fronts, (which means they're also taller than the 19s). So if you want the car to sit level the rear air suspension needs to be recalibrated otherwise the back of the car will be too low. And I believe the traction control also cares about rolling radius so needs to be reprogrammed. And the recommended rear suspension geometry (camber etc) is different with non-staggered wheels so again Tesla recommend a full suspension realignment.
     
  8. loco

    loco Member

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    Specification Sidewall Radius Diameter Circumference Revs/km Difference
    265/35-21 93mm 359mm 719mm 2258mm 443 0.0%
    245/45-19 110mm 352mm 703mm 2209mm 453 -2.2%

    That would be 2,2% difference in speedo reading and 8mm (0,31") difference in ride height. I would recommend recalibrating the suspension only if your last name is Vettel.
     
  9. Drumheller

    Drumheller Member

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    I have a P85+ and switched from the staggered 21 inch wheels to 19". I've had the car in the service center since the switch, signed the paper saying I have aftermarket wheels and tires, and was not advised of any need to re-calibrate the air suspension or anything else. One of the advisers spoke to me for about 20 minutes outside the center during which we talked about the wheels and the look on the car.
     

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