TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC
Start a Discussionhttps://teslamotorsclub.com/tmc/tags/

Lower tire pressure for last mile of super bumpy drive?

Discussion in 'Model S: Driving Dynamics' started by sorka, Feb 3, 2017.

  1. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    Last week we went skiing and the last two miles of road to get to the resort had been recently plowed but it was ice. The plow was bumping up and down creating 2 to 3 inch dips at 6 to 12 inches apart. It was *brutal* in the P85D with the plus suspension.

    I'd like to lower the tire pressure for those last two miles if the road is like that again tomorrow. I wouldn't be going more than 5 to 7 MPH and I think it will take the the ice bumps a lot better.

    I have a portable air compressor int the back that will allow me to restore back to 45 PSI (19" wheels) after I get back down to the bottom of the 2 mile stretch.

    Any thoughts?
     
  2. Az_Rael

    Az_Rael Supporting Member

    Joined:
    Jan 26, 2016
    Messages:
    2,651
    Location:
    Palmdale, CA
    Works on my Tacoma on nasty washboard dirt roads. Makes a huge difference in ride comfort. As long as you can air back up at the bottom, you should be OK.
     
    • Informative x 1
  3. jerry33

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

    Joined:
    Mar 8, 2012
    Messages:
    13,368
    Location:
    Texas
    It's a common practice for off-road enthusiasts to do so. It does save wear and tear on the chassis. The problem with doing it on the Model S is that the tire sidewalls are so short that you risk damaging the tire and perhaps the wheel as well. By driving carefully, you could probably get away with lowering it by 5-6 psi from the reading you get before you deflate. How much difference that would make is open to question though. For washboard roads, 30% would be a more typical number, but I doubt whether all the tires and wheels would survive. Sometimes you can find a correct speed on a washboard surface that will mitigate the harshness--and sometimes not.

    When you adjust the pressure back up the next morning, be sure to first take a reading before you start driving, and then again at the end of the two miles. then add the amount that it has increased. So if you are at 40 psi in the morning and at the end of the bumpy part you are at 42, inflate to 47. For many 12V compressors, adding 7 psi takes a very long time, but don't be tempted to run at highway speeds on low pressure.
     
  4. MP3Mike

    MP3Mike Active Member

    Joined:
    Feb 1, 2016
    Messages:
    3,920
    Location:
    Oregon
    It depends on the tires/wheels you have. If you have 21" wheels I don't know that there is enough "meat" on the tires to absorb the 2-3 inch dips without the wheels contacting the ice and getting damaged.
     
  5. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    I have both but the 19s are what have the all season tires :)
     
  6. Andyw2100

    Andyw2100 Supporting Member

    Joined:
    Oct 22, 2014
    Messages:
    6,564
    Location:
    Ithaca, NY
    I think you're going to be really upset with yourself if you wind up, as @jerry33 discussed, damaging a wheel or a tire. Couldn't you just take it REALLY slowly? You'd be spending time deflating and re-inflating the tires anyway, so some of the extra time you take driving slowly would have been lost anyway.

    Good luck!
     
    • Like x 1
  7. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    I took it slow. It took an hour to go 2 miles....each way :(
     
  8. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    Turned out it wasn't necessary after all. All the ice was gone. just a few inches of slush from the 8 inches of snow the night before. the d cars are rally cars in that stuff.
     
    • Like x 1
  9. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    At our co-owned lodge at Dodge Ridge. If you're wondering what the blue tape on the rear wheel well is it's 3m masking tape to keep the sand and other debris that flies off the wheel from ruining the paint at the edge. The front already has xpel ultimate so I didn't worry about it.

    [​IMG]
     

Share This Page