Why do RV makers use the Sprinter 3500 and not the 4500?

[slavitch]

Hey folks,

The Sprinter 4500 cab chassis offers 1200lb more in payload capacity and 2500lb more in towing capacity than the 3500, and costs only a few thousand more MSRP.

I notice that a lot of the Unity RV's here have ~1050lb or less of CCC. Moving to a 4500 platform would raise that to over 2100 lb. Why not use a more robust platform?

 

[Toddmc]

There must be a reason they can't. Unitys have plenty of capacity but there are premium priced sprinter based RVs with full wall slides and OCCCs under 900 lbs. If those companies could put those RVs on a heavier chassis I'm sure they would. Maybe there's no cutaway 4500 or MB won't sell it to RV makers.

 

[mikeme]

Sprinter Cab Chassis

Explore the 2024 Sprinter Cab Chassis features, specifications, packages, accessories and warranty information. Discover how the 2024 Sprinter Cab Chassis brings best-in-class productivity to commercial vans.

www.mbvans.com

 

[slavitch]

3500 Cab Chassis:
Max Available GVWR:11,030 lbs
Max Available GCWR:15,249 lbs
Payload Capacity: 6,268 lbs

4500 Cab Chassis:
Max Available GVWR:12,125 lbs
Max Available GCWR:15,249 lbs
Payload Capacity: 7,341 lbs

CCC (Cargo Carrying Capacity) is GVWR - UVW.

 

[Toddmc]

I did look at that page but a cab chassis and a cutaway are different. The cab has a wall built into the back, the cutaway leaves it open. Most RVs use cutaways, not cabs, so they can integrate the cockpit into the living area. And I couldn't find any information on Sprinter cutaways.

 

[slavitch]

it's the same vehicle.

The new Sprinter Cab Chassis/Cutaway Vans are available in 3500XD & 4500 series.

https://assets.mbvans.com/Mercedes-Benz-Vans/Brochures/2019-Mercedes-Benz-Sprinter-Vans-Brochure.pdf

 

[Toddmc]

Then I don't know what it is, but there has to be a hard limit preventing RV makers using the 4500 chassis. Look at the Airstream Atlas. MSRP is $240,000, cargo capacity is 985 lbs. As far as I know it sells for MSRP or close to it. Subtract 2 passengers, water, diesel, and propane and you have 273 lbs left. A quarter million dollars for an RV that's useless because of the cargo capacity. If Airstream could add 1000 lbs to that they would. And who would notice an $8000 increase at that price point.

 

[slavitch]

The 4500 is relatively new, so perhaps conservatism and timing?

 

[slavitch]

Also, margin.

 

[mikeme]

The point that a cutaway is different than a cab chassis is a good one.

and MB does not seem to include cutaway in public marketing information.

 

[pfflyer]

3500 Cab Chassis:
Max Available GVWR:11,030 lbs
Max Available GCWR:15,249 lbs
Payload Capacity: 6,268 lbs

4500 Cab Chassis:
Max Available GVWR:12,125 lbs
Max Available GCWR:15,249 lbs
Payload Capacity: 7,341 lbs

CCC (Cargo Carrying Capacity) is GVWR - UVW.

That isn't that great of a difference. I wonder if MB specs allow up fitters to add length to the coach with the 4500. If not, Why go with the 4500 if they can build within existing parameters on the 3500 and still leave a cargo capacity/GCWR that customers are willing to pay for? If they can add to length I still don't think there is enough difference to make it feasible to that market.

EDIT: Compared this to a F450 120" wheelbase Regular cab GVWR 15,000-16,500lbs payload 8,050-9,550lbs
F450 191.5"wb super cab GVWR 15,000-16,500lbs payload 7,860-9,360lbs*

* Super cab probably not a good class C chassis but I added it because that is the closest wheel base to the 170" MB

 

[RVBarry]

The point that a cutaway is different than a cab chassis is a good one.

and MB does not seem to include cutaway in public marketing information.

I saw a couple of box trucks at Riverside MBZ that had a bulkhead with a passthrough door, so they were probably cutaways.

 

[mikeme]

The point that a cutaway is different than a cab chassis is a good one.

and MB does not seem to include cutaway in public marketing information.

I was incorrect above.

if you go into the build your own tool on the web site, there is a zero cost rear wall deletion option, which requires addition of a shipping wall option, also $0 cost.

 

[co-kid]

I did some more digging on this topic. Here's what I learned from Advanced RV:

The 4500 chassis does have an increased GVWR. It is 12,125 lbs compared to the 11,030 lbs of the 3500XD. The limitation is that we can only build a 4500 to 9,374 lbs UVW whereas the 3500XD can be built to 10,470 lbs UVW. UVW references unloaded vehicle weight rating which is the weight of the vehicle including all permanently mounted items. It is my understanding that the 4500 is more designed for hauling cargo intermittently at higher GVWR.

 

[Scarecrow]

Here's my theory - for what it's worth. And I base this on something the Mercedes-Benz Reps said during their presentation in Las Vegas at the first Leisure Rally in the USA (I am paraphrasing): "Frankly, we were taken by surprise at the use that American RV manufacturers have put these chassis to. We did not expect them to carry such large RV houses." They built them to be vans and trucks.

They were talking more about the reasons why certain components were never made beefier - the Sway Bar, as an example. And went on to say that, yes, they agreed with some of these modifications. Although, officially, the company tries to tell everyone they will not Warranty certain changes. One example of their shortsightedness is the fact that LTV (and the others) weld on (or have pre-welded) an extension to the chassis to accommodate the overall body length. This was one of the concerns of adding a Leveling System, based on some of my readings - would those welds hold?

Perhaps the choice or design of the chassis will change as Mercedes gets more involved in the design of their own RV fleet. Assuming they follow through with those plans. I do wonder if any of these companies have designed a chassis from the ground up for the express use of the typical 25-ft Class B+ designs. I would bet money that M-B thinks it is "silly" to offer any RV on their 3500 chassis with such limited weight capacity, as it is - but they just don't say that publicly. They seemed to really not understand the American Market in this regard. That may no longer be the case.

 

[Boxster1971]

No theories needed - co-kid had the answer. RV builders don't use the 4500 chassis since the curb weight limit is lower that on the 3500XD by 1,170 lbs. The RV manufacturers must stay within the curb weight limit for their built out empty RV. This is a requirement from Mercedes engineering as strange as it may seem. Here are the numbers from the 2019 and 2020 BEG, page 43, copy attached. I don't think LTV or Airstream can get their builds under the 9,300 lbs curb weight limit of the 4500 chassis.

 

[eightyeightkeys]

No theories needed - co-kid had the answer. RV builders don't use the 4500 chassis since the curb weight limit is lower

Does anyone know why that would be the case ? Is it the weight of the 4500 frame that must be deducted from the build weight ?

 

[lostjuan]

Since the 4500 appeared I have wondered why it was so unheralded. After reading these comments I am even more perplexed. Us not being automotive engineers (I think or assume) there are things that might escape us. ie: most ford chassis cabs have a different frame, a much different rear spring setup (thusly ride quality) plus a detuned engine. Most people assume it is just a truck without a box.
So again back to why the oddity restrictions. The only thing I can think about besides liability/warranty is that this unit's origin is not North American. The European market is just different both regulation wise, road capacity/size and service restrictions. Sometimes this is better and sometimes not.
Many years ago some European countries mandated the ability to adjust headlight aiming height in a car to prevent blinding other drivers. This is way before led/hid/auto level/following headlights. Prior to pickup trucks becoming personnel vehicles here, for the life of me I could not understand why this was not available here. Hauling different size loads in a pickup truck changes the angle at which headlights cast light onto the road. Added onto that, headlights back then were dimmer than your 3rd cousin. This was noticeable to me because I drove at night for my occupation and hated being dazzled by such antiquated systems.
Traditionally in North America, bigger chassis numbers meant generally higher carrying capacity for similar configurations. I guess this might not be the case across the pond. My 2 cents.

 

[dmorean]

My understanding from the folks at ARV is that the published curb weight limit of 9300 lbs for the 4500 simply is a typo in the Mercedes publications.

 

[Boxster1971]

Is ARV building on 4500 Sprinters? The chart I posted above in 2020 was from the 2019-2020 Body and Equipment Guideline (BEG). The numbers for the 2023 BEG are much the same, copy attached. Still haven't seen RV's built on the 4500 Sprinters.