Air suspension always acts like is, or is it new?

[scottm]

I swear I used to be able to set the suspension height to Low and have it stay there for my whole trip. And the auto-lowering, once triggered, would also keep the car on Low for the trip. But more often than not, now when I check just before arriving the car has returned to Standard height by itself, after I've put it in low, or auto-lowering was triggered.

I'm think behavior changed with some software version... what's going on? I'm started to chase down the behavior to understand the way it is working now. (I am currently suffering on software level 2019.8.5 as a data point).

Auto-lowering, also auto-raises, what?!

When the car is set to "auto-lower at speed" (I set speed to 100 km/h) it goes to low like it should... and if the car slows down afterward it will auto-raise back up to standard height once some slower speed has been reached. I watched it do this. If you stay above this slower speed the height remains low. But below it, the car triggers standard height. I'm trying to determine the speed... maybe 50 km/h... Anybody know it? What I see thought is sometimes it will rise to standard but sometimes it stays on low even going slower that this trigger point. I'm thinking maybe it's a combination of lower speed being held for some amount of time before it auto-rises to standard. So if it's a quick dip on speed it won't bother doing a raise-lower cycle.

Following this auto-rise event, if you speed up again and hit the auto-lowering point, it will lower again. I think all the time. I will verify this.

Manual is not totally manual, what!?

OK, auto-lowering aside.. when I use the height setting button to lower it manually.... you'd think the car would just stay where it's put, right? But what I'm noticing is when I reach end of trip the car might have again returned to standard height. What the heck?

My theory on this is: If the "auto-lower speed" is reached after manually punching in low, the car will revert to rules of how that works (above) and cycle the car up/down based on speed. But if you punch in low, and never reach the auto-lowering speed afterwards, the car stays in low. I'm going to do a few drive cycles like that.

Then I'm going to turn off auto-lower altogether, and see if the car just stays in low "forever" after manually putting it to low. Regardless of what peak and lower speeds are reached on the hiway. If that's true, I think the question will become, when does the car ever resume to standard height? My hunch is it will take more than stopping, I think it will take more than putting it in Park, I think it may take an exit / re-entry to kick it back to standard when you put it in gear. Let's see...

 

[tonybelding]

OK, auto-lowering aside.. when I use the height setting button to lower it manually.... you'd think the car would just stay where it's put, right? But what I'm noticing is when I reach end of trip the car might have again returned to standard height. What the heck?

Can you check whether it correlates with opening your door? Just taking a guess, it might raise up to make sure the door doesn't snag on anything near the ground.

 

[scottm]

I wasn't sure if the car on previous versions of software always auto-raised when slowing down. I forget, and that's what triggered me posting to ask. For all I know it did.

But this gave a chance for me to relearn what the air suspension does, so I did some experiments and here's what I got. It would be interesting to know if the "new air suspension" (gen2 air) acts the same way... anybody got it?

On gen1 air:

If auto-lowering has a speed selected (can be 80+ km/h) ... then the car lowers when that speed is reached. And it will auto-raise (back to standard height) immediately when speed drops to 60 km/h ... Rinse, and repeat as you speed up and slow down the car yo-yo's accordingly. When you park, the car will be at standard height... unless you've geo-located a raise height event at that spot.

If the auto-lowering slider is all the way to the left, "Always" position, you'll get an "are you sure?" (limiting Tesla liability) warning. If you say yes, there is no auto-lowering. The only way the car goes to low is by you punching the low position on the suspension screen. The car stays low at any speed from then on, even if you park it, get out, and come back the next day... still on low. You have to raise the car yourself to standard height, or higher. Or if you hit a geo-located raise point (and you're driving slowly enough) the car will stretch legs up to high or very high (skipping over standard height).

The UI shows (but barely shows - grey on grey) what heights are eligible for manual or geo-located raising. My car will allow high setting up to 55 km/h. And it will allow very high up to 35 km/h. Beyond these speeds, these heights are non-options on the UI and geo-raising will ignore them accordingly if you blow through that point at higher speeds.

gen 2 work the same?

 

[scottm]

...so what I decided to do was add lowering links.. the car is now effectively riding in what used to be the low position - it's the new normal. And I moved auto-lowering slider to "Always".. because I'm already low.

Now if I want super low and scrape bellies like a Corvette, I punch low on the UI and put on sunglasses, even at night, because it's that cool! And I think I've gained 1% efficiency on battery, so I get 4 extra kilometers per tank now.

 

[Terra117]

My 2015 P85D has always done this. I set it to Low, exceed the automatic lowering speed, then once I get below the automatic lowering speed it goes to Normal.

The service center said to turn off automatic lowering and have it always set to Low. It works.

 

[scottm]

Another data point about auto-raising when the auto-lowering is on the Always setting... that I just confirmed:

If the car is at Standard height when you hit an auto-raising geo point, the car goes up to new height, and after that if you speed up and exceed that height's limit, the will go back down to Standard.

If the car is at Low height when you hit an auto-raising geo point, the car goes up to new height, and after that if you speed up and exceed that height's limit, the will go back down to Low.

So "Always" means:
Keep the car at the height you manual select. Until you select a different height, or hit a geo-raise point.
If you hit a geo point and speed up enough after that, the car goes back to where you had last set it manually.

Nice.

 

[Kipernicus]

My car automatically lowers a few minutes after we get out and doors lock. Maybe it is more accurately returning to a normal height now that it doesn't have to deal with our weight.
Either way, if I park over a curb, it will settle right onto it and scrape when I pull out.
One time I had backed in, and it scraped so hard on the curb that the chrome bit underneath got bent out
(I foolishly didn't stop the moment I heard something not right)
So I tried to bend it back and now it hangs down a few cm. Not aerodynamic but probably not worth however many hundreds it will cost for a new one.