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,
I have air, and my last two loaners were springs. Greatly prefer the air over the coil springs personally because the freeway and bumpy pavement ride is so much nicer. I have a non-performance S with 21" continentals.
It should be easy to test drive both but I think unless you are primarily interested in cornering performance (in which case you should be getting a P or P+) you'll love the air.
ps. I have tracked my S85 and it handles very nicely for such a heavy car. Very little body roll, excellent braking with no fades, super acceleration...... except the limiter comes on after the first 3 laps :-(
I just took delivery of my P85 with air suspension. I guess I do not understand the concept in this car. If I drive more than 5 MPH the suspension automatically lowers to standard. I just had a MB S550 and once the suspension was active, it stayed at the higher level until I choose to disengage it.
What is the point of being able to lift the car only momentarily? What if I want constant clearance in snow conditions? I can't maintain the height and there's no setting to keep it engaged. Thoughts? Am I missing something?
@allenjohansen: They did not raise the car, and nowhere is 3". They just changed the parameters of when the car is lowering to low.
and 1/2'd the amount Low lowers the car :)
I agree, there should be an available advanced setting that allows the owner to customize the air suspension setting. I would love to have the car go lower at a lesser speed and also allow the car to stay raised up to high or very high at any speed that I choose (especially if I'm driving in the snow or on a road with potholes). Tesla is being a little too protective here.
I routinely use the air suspension to raise the car to get into steep driveways and for loading onto ferries. It seems that we can keep it in "Very High" up to 8 or 9 mph, which is adequate for ferry loading and steep driveways. I don't recall at what speed it changes to standard height, but it is a higher speed.
I think that there has to be limits to the speed in high and very-high mode to accommodate for the air suspension taking care of its other tasks associated with bumps and potholes.
I have the air suspension, I see no benefit.
It was pointed out by allenjohansen that the 'fix' was for the car fires was to 'raise' the suspension by 3". This is factually incorrect. The air suspension 'standard' setting - the lowest 5.8 allows, and which was unchanged in 5.8, is the same height as the coil suspension.
I actually think the air suspension feels less connected to the road than coil suspension, and without any statistics to show the benefits of the now gone 'LOW' setting, I'm not sure what other than raising the car to avoid curbs is.
We have ordered it because :
- the usual reasons mentioned in all air suspension discussions (steep driveways, heavy snow, etc.).
- if we ever have to carry something heavy in the trunk, our S will stay level hence have more even tire wear and also avoid blinding other drivers at night because the vehicle is not level any more (very important point as we hate to cross vehicles that blind us);
The energy efficiency never came in play when we decided to opt for that option.
I do hope that Tesla allow a bit more control over this air suspension. The bulk of my driving will be in and around Brussels which is bedevilled with cobbled streets, potholes, tram-tracks and speed humps; not to mention the kerb I have to get over to my drive which then slopes downwards...
So I would prefer to keep it on maximum height until I'm outside the city.
I am reasonably sure the alignment specs call for a higher ride height on the coil cars than air at Standard. This is also the reason air cars have higher spec'd negative camber values resulting from the lower ride height and camber gain in the suspension.
Does someone have Tesla's alignment specifications with ride heights to confirm?
I have an audi A5 and I can't find any ground clearance specs on it. I have a steep driveway, which, if I hit at an angle is no problem. Is the MS lower than an A5? I didn't order the suspension with my 85, but I'm thinking I need to, if its not too late.
If you are looking for custom air suspension, check out our website. We can get a universal air strut to fit the Tesla car.
The manager at my Tesla store told me that air suspension is a total waste of money. So unless you have serious clearance issues, or want to be able to make your car ride like a Cadillac, think twice. Or buy a Cadillac.
@Gadfly: Not sure about it being a total waste of money. I have it in my Mercedes and we'll get it in our Tesla. Once you get used to the feel you don't want to go back to coils. It is also helpful to be able to raise and lower the car as needed. I personally consider air suspension essential.
I opted to go with the standard coil suspension. Number one reason is long term cost and maintenance associated with air suspension. Second reason is the ride difference is negligible (IMO).
Me to, I don't care if it's at a party or at home, you will come upon a driveway that requires a bit of lift so as not to touch down. Coils can not do that.
Also, I love the option of changing the driving experience, not sure you can do that with coils, go from a Lexus ride to a Porsche ride?
@NO2PTRL - I'm a fan of air (which I have), but I don't see how you can change the type of ride. I only have options for ride height - not softness of ride as a few other car maker's offer.
Use sport steering and low setting and you've got a sports car. Use relaxed steering and high setting and you've got yourself an ELR.
Talk about Zombie threads! This thing is three years old!
@Thomas: To really have an ELR experience you'd need to limit pressing the accelerator pedal only half the way down :)
Thank you for clarifying that Thomas N.
That is what i meant, i love that you can do that.