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Coil springs vs air suspension

Discussion in 'Model S: Driving Dynamics' started by artsci, Sep 14, 2016.

  1. artsci

    artsci Sponsor

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    While my car is at the Rockville Service Center for a fix the the totally failed nav system I have a loaner with coil springs.

    I wasn't aware of it until I started driving the car but the difference was immediately apparent. The coil springs result in a substantially rougher and noisier ride and bumps result in jolts which are much less felt in my air suspension car. Based on my experience with the coil springs I definitely prefer the air suspension.
     
  2. LastGas

    LastGas Member

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    I got the same impression when I test drove air and coils. Air is smoother and quieter. I like smooth and quiet, and I ordered air. Delivery in 12 days.
     
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  3. Ulmo

    Ulmo Active Member

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  4. DJung

    DJung Member

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    I had the same feeling, I have coil suspensions and the air suspension loaners I got were very smooth. It was especially apparent when going over large dips and bumps. There are these really annoying thin stubby speed bumps in a parking garage that I frequently park at. They look like this:
    [​IMG]
    They are a real pain on my coil suspension vehicle. I have to pretty much stop in front of it and creep over the bump or else it results in a really nasty drop and sudden jolt. With my air suspension loaner, going over them was an absolute breeze. Also on the freeway there are large dips especially where the freeway meets a bridge. In my coil car it is a really hard jolt especially at freeway speeds and it surprises my passengers.

    I did hear that newer vehicles had softer coil suspensions but I haven't tested one firsthand. The suspension choice was my only regret, I wish there was a way to at least retrofit the newer coils that are apparently more smooth (And if it doesn't cost an arm and a leg).
     
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  5. GasKilla

    GasKilla No Gas Know Peace

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    I have a 2015 MS with coils delivered in December, just had a 2013 P85 loaner with air ... I thought the air was "mushy" and not as tight as my coils. But I got the coils for the long term reliability (don't want to pay to get air suspension fixed in the future) I will say the coils are a bit "bouncy" but overall it's very tight and handles well, no slop in the ride. The air felt "sloppy" but to each his own ....
     
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  6. Max*

    Max* Autopilot != Autonomous

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    I have coils, but have had loaners with air.

    Regular driving? I didn't notice much difference, which is why I went with coils originally.
    Over speed bumps air suspension wins hands down.
     
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  7. gnelson

    gnelson Member

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    My P85+ with air suspension is far from mushy. I get no bump steer. I bet I would experience bump steer with coils.
     
  8. scottm

    scottm Active Member

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    Off topic, but you brought it up... my Nav did that and cure was a center console replacement. I decided to upgrade to LTE at the same time (on my nickel of course). But, curious to know the remedy was for you.

    And since we're off topic, but this is kinda related... and now that you're home again, how big are the air suspension link ball ends? (.. I never forget ... ;) )
     
  9. artsci

    artsci Sponsor

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    Here is the parts list for fixing the GPS:

    Part Quantity

    LIFTGATE GLASS (6005898-00-F) 1

    CENTER HIGH MOUNTED STOP LIGHT ASSEMBLY (6005917-00-E)

    1 DOW BETALSEAL

    I'll measure the ball ends tonight and post.

    Rick
     
  10. Cyclone

    Cyclone Active Member

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    I've noticed the same with my car with air vs. others with coils. I too worry about long-term reliability of the air. However, I figured that if I own my S out of warranty and the air failed, I could just switch to coils and move on. @lolachampcar purposely changed his to coils, so I could do the same out of warranty.
     
  11. SoccerMan94043

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    I was worried about this when I purchased my S70D. So I test drove two S70Ds (one with and one without) and two X90D (also one with and one without) and took them all through the same stretch of rough road, back to back over an hour test.

    I literally could not tell the difference. I even tested low vs. med height on the cars with air. Still could not tell the difference.

    Ended up getting coil.
     
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  12. David29

    David29 Member

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    My car (2015 70D has coils and I have experienced a somewhat rougher ride than I would have preferred (in comparison to previous cars -- MBs with steel springs) and I have driven air suspension Model S vehicles. But I regret that I did not do a thorough test of air suspension over particularly rough roads that i drive regularly, so I do not have a valid basis for comparison. The tested 70D seemed "OK" so I ordered it that way.
    My advice to prospective buyers to to do such a comparison -- it is a potentially major difference in the cars, and a costly difference if you buy air and don't need it.
     
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  13. Cyclone

    Cyclone Active Member

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    I think this is key. One decent roads, the difference between the two would be much less noticeable and could be in the "noise" range for many people's butt-meters. But go over rough roads, uneven roads, and speed bumps (like I do), and you notice the difference more. I'm happy with my air, I do ok with any loaners with 19s, I prefer 21s to have air, and I actually told the service center to never give me a P85+ with 21" coils (a unicorn) ever again.
     
  14. Skotty

    Skotty 2014 Model S P85

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    To me, the air suspension was unnecessary added complication, and there wasn't anything I could point to that would make it superior for my preferences. My one concern was whether or not there would be places where the added height that air could achieve would be a big benefit, but I find the coil cars clear obstacles reasonably well (they clear a standard height curb and don't scrape on the wacky inclined driveways that my Volt did scrape on), so that concern turned out to be unfounded. So I happily got coils.
     
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  15. lolachampcar

    lolachampcar Active Member

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    I actually pulled the air springs off my P+ and put on the coils (keeping the P+ dampers) because I thought the air springs were too mushy. It must be a porridge thing :)
     
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  16. Petra

    Petra Member

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    I can see why... I had a P85+ loaner while my 70D with coils was in for service and the P85+'s air suspension was a floaty mess. Yes, it was far less harsh than my coils, but the floating feeling from the active air suspension was really annoying (you could feel the subtle but never ending oscillation as the car worked to correct road unevenness).
     
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  17. jmsurpri

    jmsurpri Member

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    Not sure what you felt there, but I don't believe there is a ton of 'active'ness in the air suspension. It sets up the ride height initially on startup (if the weight distro has changed since last drive), and I've never heard it do much more than that during the drive. I've heard it will try to self level on cornering but I can't tell if that's happening.
    I have air and 19s and feel the ride quality is much harsher than the car I test drove which had air and 21s. I feel every little imperfection in the road as a harsh jolt to my body. There is speculation that Tesla might change up the suspension components and there can be big difference in ride quality on the same spec cars, so it seems like you never know what you're gonna get. For example, I've measured 26mm front sway bar diameter on my 85D which seems to be much larger than even P85D sways.
     
  18. Uncle Paul

    Uncle Paul Member

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    So many variables that it makes a simple coil VS. Air suspension a difficult comparison.

    All these things, in addition to the suspension choice, will make significant differences.
    Date of manufacture...Tesla constantly changes ride compliance.
    Model...P rides rougher than regular.
    Tire size...smaller ride better than larger.
    Seat choice...There have been several changes to the seating over the years. Standard, improved springs standard, next generation, contour, model X seats.
    Road surfaces. Some regions have better roads than others.
    Tire choices...Michelin, Continental etc.
    Individual tire inflations.

    Not so easy to just say which is better.

    Friend had Mercedes with air suspension. Loved it until he had to replace several after warranty.
     
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  19. LastGas

    LastGas Member

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    The other part of the story is the height adjustment. The coil version of the Tesla is lower than my Prius that scraped bottom all the time--very disconcerting. I could imagine a convex driveway entrance being even worse with the longer wheel base of the Model S. With air suspension, I can raise the car .7" higher than the Prius. Not much, but at least not lower.
     
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  20. GasKilla

    GasKilla No Gas Know Peace

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    I should have mentioned the loner I had was a P85+, looks like we were eating the same pooridge
     

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