Advanced RV Air Suspension a Dually First for Sprinter?

[Davydd]

The latest Advanced RV 4 cylinder that is going to be driven to the Tampa RV show will also have a new air suspension system according to this article and video on the Advanced RV website. When I bought my dually Sprinter in 2011 there were no air suspension after market installations available. This one is from Europe and replaces leaf springs, anti-sway, chassis-axle alignment, and shock absorbers. It is electronically controlled and has a 6" up/down range. It is also suppose to keep your RV level automatically with variable loads. According to the linked video in the article there are only about 2 or 3 installations in the United States and around 11,000 in Europe. It is Mercedes Benz approved and serviced.

Advanced RV Installs VB Air Suspension on 2014 Sprinter Chassis

[bobojay]

Saw this last night...$$$$$$$

[booster]

That has got to be a spendy upgrade. Advanced may be on their way to making the first $200K class b

It does make sense to use air ride, though. Trains and trucks have been doing it for years to get smooth ride and variable load capacity at the same time. Tying it all into shocks and ride control and such, to me, makes it too complicated and expensive to maintain. As lots of Navigator owners have learned, if you pop and air bag, you don't go anywhere until you fix it, or go very very slowly.

[mlts22]

Originally Posted by booster

That has got to be a spendy upgrade. Advanced may be on their way to making the first $200K class b

It does make sense to use air ride, though. Trains and trucks have been doing it for years to get smooth ride and variable load capacity at the same time. Tying it all into shocks and ride control and such, to me, makes it too complicated and expensive to maintain. As lots of Navigator owners have learned, if you pop and air bag, you don't go anywhere until you fix it, or go very very slowly.

Learned that one with an old Town Car. Pop an airbag, and there is a definite reason that the old carriages with no suspensions are called boneshakers. I wish them luck with the full air suspension.

[Davydd]

I suppose anyone can add the air suspension to their Sprinter. This is the company, VB Airsuspension. Advanced RV said they could retrofit existing Advanced RV Sprinter owners. They didn't mention any Sprinter RV owner as they had with screen doors and such.

I had the Firestone airbags on my 2005 Pleasure-way Plateau but they were not as sophisticated as these. They didn't give me any 3 inches of travel up or down or adjust automatically with the load. If the VB system did all they advertise it might be worth it. There is no front air suspension so you can't raise the whole B up level.

[booster]

There are quite a few variations of air ride suspensions out there, some better, some not so better, IMO.

Plain old airshocks work OK, but are really a big compromise because you can't get much area for the air support, and the shocks get effectively smaller because of the space used for the air parts. They don't leave you stranded if they fail, though. There are many better choices out there, IMO.

We are all familiar with the add a bag to leaf springs like Firestone and Airlift that we put in our vans. They work well, have the springs left as backup, but are limited to 2-3" of lift. They can be automated if you cared to get automatic ride height. They don't mess with any of the suspension geometry, shocks, or swaybars. Cheap and effective.

Our 1996 Buick Roadmaster wagon used factory installed airshocks with auto levelling control and compressor, added to the original trailing arm coil spring rear suspension. Most of the weight was still on the springs, so you have backup if it fails, which it did. I replaced the airshocks with normal ones and put airbags inside the coil springs, which works very well. The auto level also failed, so it is now a manual fill setup. This was a cheap way to make auto height for Buick, but not the best design.

Quite a few factory vehicles use a full air ride system designed from the ground up, many with all the goodies of auto level, etc. Very nice, but very complex, and can leave you stranded if they fail.

The system mentioned apparently had the goal of totally removing existing leaf springs, which makes it one of the most complicated retrofits to do. Leaf springs are not only the springs, but they are axle support and guide. They determine the amount rear steer in corners. If you replace them with bags, you have to provide all that axle mounting and guiding hardware. If you go to the specifications sheet in the link, it shows that they went to what looks like independent trailing arms, with a cross support between them behind the axle, making it almost a single trialing arm setup. Normal looking airbag setup, but lowered and put behind the axle to get the extra travel compared to the 2-3" you get if you go above the axle. Normal shocks, normal sway bar, compressor and ride height transducer, more than likely. It does not look to have any really fancy dynamic stability type control built in, which the statements seem to imply a bit.

The only potential weak spots that I see, are that they seem to have given up some of the side to side support for the axle, because they lose the support of the rear leaf spring mounts. It also moves all the weight to one spot that originally had none, but I would have to assume that MB approved that. As mentioned, there is no backup for the bag, so if you lose one, you are pretty much done until you can get one. The good news is that it looks easy to change. The compressor looks to go behind the axle, so you lose that area of the underbody.

Hard to guess a price, as MB and other European stuff can be really spendy sometimes, but I would guess in the $5-10K range, installed.

[pattonsr]

The Mercedes factory does install the air suspension if the PL9 option is specified. This would bring the price down. However I am not sure if the US will be allowed to specify air suspension or if it will remain as an add on by the dealer or up-fitter.

Mercedes AWD is coming to the Sprinter world at the end of 2014. It is like the 4MATIC on the GL350 except it is not full time. The GL350 also has air suspension.

[Davydd]

Hopefully we'll know more after the Neundorfers take their Ohio to Florida and back trip in their latest Advanced RV with a 4 cylinder engine and air suspension. It's nice that the owner of the company is applying his direct experience toward his product.

I am hot and cold on AWD desire. I need it just to get up my driveway most of the time this time of year but at the same time don't really desire to drive my B around in the salt laden streets. So it sits most of the winter. I don't mind boondocking but that doesn't mean going down roads that require AWD. I would think they would shake up your systems and storage doing so. We've had nothing but AWD and 4x4 for the past 20 years or so for cars and pickups.

[bobojay]

Having that Subie AWD has probably spoiled you because nobody else that I've heard of make a system that works as well as theirs. I doubt the MB system works as well

[Davydd]

Some positive information is starting to come in on the air suspension. Advanced RV has installed it on 3 Bs so far. Sounds expensive, like around $7,000.

http://www.advanced-rv.com/mikes-blo...-voyage-day-1/

[booster]

Originally Posted by Davydd

Some positive information is starting to come in on the air suspension. Advanced RV has installed it on 3 Bs so far. Sounds expensive, like around $7,000.

http://www.advanced-rv.com/mikes-blo...-voyage-day-1/

Interesting article. The reduced sway would be a good thing, in any B. I would assume in this case the reduction comes from a higher rate rear sway bar, as that was part of the conversion IIRC. I know several folks have reported greatly improved handling and much less sway when they added a big rear bar to their Sprinters. The rocking on driveways and such that was mentioned is very familiar to us. Our Chevy had the same feel of a big rocking motion when going up drivelways or right turns with deep gutters, and a big rear bar took it right out. Airbags in themselves shouldn't really affect sway, as they are just independent springs. They should, however, improve ride and reduce progressivity if designed right, which these seem to do.

What I did find very, very interesting was that the 4 cylinder diesel was turning 2250 rpm at 65 mph, in top gear. I would guess that the 6 cylinder is much less than that as the torque peak is something like 1200 rpm. The 2250 is actually slightly higher rpm than our Chevy gasser with a 4 speed transmission, and the newer gassers with 6 speed transmissions run considerably lower than we do. Obviously, this diesel has a lot less torque, so they make their horsepower with rpms, like a gassers normally do. I would expect that to increase noise and reduce efficiency to some degree, but we will see over time. VW has used higher rpm diesels for a long time in their cars, so it is not unusual, but not expected (to me anyway) in a heavy van. I seem to remember a road test where they compared the 4 to a 6 cylinder on a hill, and there was a huge difference, but I don't recall the details. It will be interesting to hear how they do in the mountains, where it really counts to have horsepower available.

I certainly wouldn't expect the folks from Advanced to sharply criticize the air ride or 4 cylinder, but it will be interesting to see how they steer their customers as time goes on. I know Roadtrek was OK with putting the 4.8 liter engine in the extended Chevies for a while, but it kind of quickly faded out to only being in the shorter vans, or reduced cost models.

[Davydd]

The 5 cylinder Sprinter and the V6 both run over 2200 rpm at 65 mph. The 2250 report did not seem unusual, at least to me. They were driving the extended body Sprinter which is 24'-1" long.

Here is another short report on day 5. They reported better mileage but claimed still bucking head winds most of the way and heating the B inside continuously with the diesel Webasto heater. Still, at over 21 mpg it looks promising. I was unaware they had an exterior storage compartment built into the skirts which looks comparable in size to what I have in my Great West Van Legend. They evidently are using one of those electric induction portable stove tops in this B. I'm not sure if they completely eliminated propane on this one or not.

http://www.advanced-rv.com/mikes-blog-2 ... oyage-day/

[booster]

Originally Posted by Davydd

The 5 cylinder Sprinter and the V6 both run over 2200 rpm at 65 mph. The 2250 report did not seem unusual, at least to me. They were driving the extended body Sprinter which is 24'-1" long.

Here is another short report on day 5. They reported better mileage but claimed still bucking head winds most of the way and heating the B inside continuously with the diesel Webasto heater. Still, at over 21 mpg it looks promising. I was unaware they had an exterior storage compartment built into the skirts which looks comparable in size to what I have in my Great West Van Legend. They evidently are using one of those electric induction portable stove tops in this B. I'm not sure if they completely eliminated propane on this one or not.

http://www.advanced-rv.com/mikes-blog-2 ... oyage-day/

The higher rpm on all the engines is a surprise to me, not as much on the 4 and 5 cylinder, but a lot on the V6. I has to be putting all of them over their torque peak at highway speed. What is the redline on these engines?

[Davydd]

I believe the stated redline for the Sprinter is 4200 rpms. I'll have to check my tachometer later.

[bobojay]

Originally Posted by Davydd

I believe the stated redline for the Sprinter is 4200 rpms. I'll have to check my tachometer later.

David is correct here. At 3900 rpm though, the V6 is really screaming and gets a bit course feeling, (both of ours have)
Both of the Sprinters we've had, 68 mph is right at the perfect rpm for efficiency

[Davydd]

Here is an update on the Advanced RV trip from Ohio to Tampa with the air suspension. Not a lot of new information.

http://www.advanced-rv.com/riding-on-ai ... otor-home/