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What do you guys keep your tire pressure at 20 inch Continentals.

Discussion in 'Model X' started by Modelx2016, Aug 5, 2016.

  1. Modelx2016

    Modelx2016 Member

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    The sticker on the door says 42psi when cold which is what I have it set at right now. Any range benefit if the PSI was increased?

    I have the 20 inch Continential tires with the helix wheels.
     
  2. scottf200

    scottf200 Active Member

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    I do 43/44 so that is 46/47 as they warm up. I am getting very good wh/mi with these tires. 321 wh/mi on my recent 2340 mile roadtrip from Chiago IL to Asheville NC and staying there going every direction for hiking and waterfall viewing.
     

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  3. rainforest

    rainforest Member

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    The door says 42psi, but my SC keeps pumping them up to 45 psi. Are there any benefits to pumping higher than 42psi?
     
  4. BAven8068

    BAven8068 Member

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    I've noticed them doing the same to mine. I lowered them back to 42 a couple times after they did this, but now I just leave them at 45.
     
  5. McManX

    McManX Member

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    Mine are at 43/44 and warm up to 45/46. Similar efficiency as above.
     
  6. FlatSix911

    FlatSix911 918 Hybrid

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    If you want to improve your actual range ... set the cold pressure at 45 psi / max hot pressure at 50 psi :cool:
     
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  7. commasign

    commasign Active Member

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    46 all around.
     
  8. dhanson865

    dhanson865 Active Member

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    #8 dhanson865, May 22, 2017
    Last edited: May 22, 2017
    First off if they drove the car then set the PSI they are setting it hot to 45, not cold to 45. Totally different when and how you check the PSI.

    I don't have an X but on all my current cars I tend to stay between door jamb and sidewall max. Which means I'm running higher than the average driver of whatever car I'm driving in. So if the service center set me at 45 and the sidewall max is 51 I'd stay in that range (when measured at the coldest time of the day, with tires not driven on recently). If you check them and they were 45 hot, but cool down to 42 in the middle of the night then they really did set them to 42. In that case I'd use the cold number to start my comparison.


    As to the question of what Higher cold PSI gives you:

    * better resistance to heat changing PSI
    * more range (longer coast, more regen, less power to maintain speed)
    * increased resistance to hydroplaning (to a point, then when severely overinflated braking gets worse than recommended PSI)
    * improved handling in some conditions (more precise steering and better cornering stability to a point, too high gets into over steer)

    - increased risk of puncture by foreign objects (flat tire)
    - increased risk of damage when hitting a pothole
    - possibly harsher ride (air suspension will hide this negative)

    = Will move wear towards the inside of the tire. Depending on the weight of the vehicle and the PSI used this could increase, decrease, or not affect tread wear life. If you are replacing tires because of how Tesla aligns the vehicle causing excess wear on the tire edge, a higher PSI might extend the life of the tires.

    The range difference is more noticeable at low speeds, at high speeds aero effects dominate and will make the tire PSI less important to range.
     
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  9. FlatSix911

    FlatSix911 918 Hybrid

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    I thought that higher tire pressures were better able to resist pothole damage?
     
  10. Murbs

    Murbs Member

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    I use 3 Bar cold (~43.5 psi)
     
  11. travwill

    travwill Active Member

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    I did 42 all around when very cold, and I'm getting 45/46 as it warms up now and on longer trips. Likely a tiny bit higher when it really heast up out.
     
  12. dhanson865

    dhanson865 Active Member

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    #12 dhanson865, May 23, 2017
    Last edited: May 23, 2017
    Most anything having to do with tire pressure range is some sort of U shaped curve.

    If the PSI is super low (near the point of not being able to hold pressure and falling off the rim) and the rim is closer to the ground then potholes are very very likely to cause damage

    If the PSI is super high the tire won't flex as much then potholes more likely to cause damage than proper PSI but less than the severely under inflated end of the curve.

    In the middle of the curve moving higher probably reduces risk. At some point higher PSI stops helping and starts making it worse.

    Really wide rims with low profile tires compress the U curve with greater chance of damage at both ends.

    Narrower high profile tires widen the acceptable PSI range (if they aren't hitting a weight limit / max load issue). More rubber in the sidewall gives more flex/shock absorption before the tire is fully compressed and that could dissipate force before damaging the tire and/or rim.

    The key thing is there are dozens of curves you could plot and overlapped you'd see the sweet spots all over the place. It's a trade off of one vs another no matter what PSI you choose. Plenty of room to move around a couple of PSI this way or that to find what works best for your vehicle in your weather on your roads with your driving habits. But my rule of thumb still remains door jamb is my low PSI and sidewall max is my high PSI. I work in that range.
     
  13. FlatSix911

    FlatSix911 918 Hybrid

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    Agreed. I set my cold pressure at the Tesla recommended 45 psi and the hot tire pressure is 50 psi displayed on the dash IC.
     

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