Does anyone know the pros and cons of air suspension?
I do not have first hand experience, but one obvious advantage seems to be the flexible ride height. At slow speeds ride height can be increased for greater pothole safety and increased maneuverability in parking lots. At higher speeds, the ride height should be decreased in order to optimize aerodynamic drag.
I am not sure if "air suspension" alone already implies that the ride height is adjustable. In any case, I hope that it is in the implementation in the Model S.
I am very curious myself and am looking forward to other posts in this thread! Who has experience with this kind of suspension?
(It is certainly not the Bose active suspension, although that is real cool, too... ;-)
I discussed this with the rep at the October event. The air suspension will adjust ride height depending upon the speed of the car, cargo weight, etc... He was saying that it also promotes more stable cornering but I can not recall his explanation as to why. I am sure there are some guys here that can explain it.
From the model S Features page: "The optional air suspension automatically responds to speed and road conditions. As Model S accelerates, it lowers the vehicle for optimized aerodynamics and handling. Lower or raise Model S using the touchscreen to unload cargo when parked."
I guess a con would be that it's more complicated, so harder/more expensive to fix if something breaks.
The Bose active suspension would probably use too much power from the battery. It needs an extra generator to work on an ICE car.
Lincoln had speed adjustable air suspension in the 90s. Main problem was that after a few years, the bellows leaked and the repair cost more than the old Lincoln was worth. I raised the point with the tall German Tesla person next to the naked drive train at the October event. He naturally assured me that the Tesla bellows would last many many years. I hope he is right because I expect to get the ride height suspension.
I have a Ford SUV with air suspension. Supposedly lowers the car at speed, but I've never noticed the difference. Ride height under load is another matter. You can feel and hear it in action when you fuel the car. (full tank adds 100 pounds). As the rear of the car starts to drop under the load, the ride system starts up and relevels the car. We've forklifted a full pallet of stone in the back which dropped the car almost to limit of the springs, and the suspension brought it back to level in a few seconds. Without having the suspension stiffen under load, the greater sprung mass would have been insufficiently dampened, bouncing around like the head on a jack-in-the-box. Not a good thing when you've got 1500 pounds of stone in the car.
The Audi Allroad has a fully adjustable Air Suspension, when at its highest setting, the vehicle has more clearance then a BMW X5. With Winter tires, it handles any Whistler snow dump, no problems. It also automatically responds to speed and road conditions. I would hope that the Tesla S will also have override setting capabilities. Incidentally, there are many other road conditions and situations in which higher settings are advantages, off-road, salt\sanding, gravel, huge rainfall, entering and exiting(curb clearance), parking (front\rear end clearance) washing and simply keeping it clean....!? It's a great option that every well engineered vehicle should have!
Given the absolutely flat undercarriage and low centre of gravity, it's a natural pairing with the Tesla S chassis and suspension.
I had air suspension in VW Phaeton just sold. Ride is smooth, speed bums does´t matter, you can clear then with much higher speed conformtably. Stiffness can be adjusted from american style soft to pretty rigid near sportscar-typed. Level adjustment is pretty useless, in VW highest level will loose lot of suspension, it will be too hard and mentioned for only moving car in snow etc. With Phaeton´s active suspension and 4WD, 250km/h feels very safe speed, smooth and effortless ride. Where as BMW M6 is intolerably "active" and needs constant guidance with two hands on the steering wheels and sweating.
More part, more problems and also more expensive problems. Under warranty, compressor broke down in cold weather (-35 C)and was fixed, repair was around 2 800 EUR/4 200USD, fortunately paid by the VW. Also suspension level indicators were connected to Xenon lights, one indicator broken, headlights started to adjust themself.
If normal suspension is as good as they say, I might even avoid air suspension. You have to remember that TM is a newcomer in air suspension and will have many problems in the beginning. More tech, more problems and service still far away in Europe.
Any ideas on what the cost of the option might be?
I can't recall where I read it, but I believe the air suspension option on the Roadster goes for $6,000.
It's not an air suspension option on the Roadster, it's an adjustable suspension option.
Found it on the Tesla Motors Club forum.
Of course it remains to be seen if the Model S will price out the same.
Sorry for the false alarm.
Some people do claim that traditional coil and shock suspensions are more predictable as far as handling goes, but the air suspensions probably ride slightly better.
Air suspension are nice to have, but very expensive to replace. Used to have MB E500 that cost $1500 to replace only 1 unit from MB dealer. Replacing 3 other units will easily add up to another $6000 to the bill. I think I am going to pass air suspension on my S order, since reliability will be an issue on Tesla's first car offered with air suspension system.
I think it will be rock solid and any issues will happen pretty quickly and thus be covered under warranty.
Since maintenance for the car has a single source, Tesla, I'm going to be extending the warranty as long as I can.
Newer Magnetic suspension technology is the way to the future. Tesla should use magnetic suspension instead of air suspension that won't last long.
At some point I'm sure they move to that tech, but Tesla is not for new gizmos, they use proven techs. Magnetic suspension like that Bose system is new.
As funny as it might seem, they use old techs in their cars, just improve a bit here and there and as a whole make old tech look like new. I don't think there is anything really new in any of the Tesla cars, just combinations might be unheard of like using 17 inch touch screen in a car.
(of course this is all relative, all ICE cars are from dark ages compared to Tesla cars).
@Timo: I'd wager that the engineering solutions imbedded in a modern high-end vehicle are collectively "tougher" (by some reasonable metric) than what Tesla had to solve. The difference is that those ICE solutions have been 100 years in the making.
I think the PES design is uniquely Tesla, and is the "secret sauce" that makes the drive trains so attractive to Toyota, MB, etc.
Yes, but it isn't anything new, it is just better. I think. It could be that they have something completely new in there but I believe that it's just combination of software and hardware just assembled better than other manufacturers similar thing.
Exactly, Timo; I'm not minimizing the achievement of the Tesla engineers, but its two orders of magnitude simpler than, say, the Audi RS8 powertrain. (Which is a good thing.)
I am still wondering about the air suspension. If I remember correctly, before the air suspension was announced, someone here in the forum pointed out that air suspension would not be possible in the Model S due to the lack of the ICE -- because you need a powerful compressor for this technology. Am I mixing things up?
How ever it may actually work, air suspension will need more energy then a classic passive spring suspension. How much? I consider getting the air suspension to reduce air drag at higher speeds and thus improve range -- but will this actually buy me more range (at, say, 85mph) or will the reduced air drag just barely make up for the range that is lost due to energy required to power the air suspension?
I know, any answers will be highly speculative, but while we are waiting for more official information, we might as well kill some time speculating...
Air suspension will only require power to raise the car. Once the car is at a set level, then the air is just held there. It's not like the compressor would be running all the time.
If one declines the active air suspension option for Model S, what does that mean? Do you get a fixed high or medium level height for the suspension?
When you raise the car to "high" you must drive less than 18mph
or the air suspension goes back down to normal.
I have a small question. Has anyone actually tried both air and normal suspension?
If anyone has gone for the normal suspension, could you give a quick recap here? I'm sure hundreds of people, if not thousands, will appreciate that.
(there are no cars delivered to europe yet, and the test cars have air suspension.)
I set the air suspension to very high every time I pull into a parking space with a curb.
And was glad to have it last weekend when we had flooded streets - and the extra 1+" clearance gave a little more margin for error through the standing water.
A few new owners are reporting that the standard suspension performs excellently, but there are no detailed point-by-point comparisons with air yet.
Here's a current discussion on TMC: http://www.teslamotorsclub.com/showthread.php/13015-Active-Air-vs-Standa...
I have just signed a sales agreement for a new Tesla with air suspension, and with the fires they have had, and the fix is to raise the car 3" , what good is the air suspension,& is still worth the extra money,