GVWR question

[mjracsj]

We have a 2011 Berkshire 390 RB with 340 hp engine. Like all Berks of this size and engine the gvw is listed as 28,000 lbs. Worrying that we we near this when fully loaded (full fuel, LP, most of our cargo & gear, 1/3 fresh water and empty gray and black holding tanks) I stopped at a CAT scale and we came in at 27,740. This was without our bike rack or Blue Ox towbar attached and without much in our personal luggage and food provisions. Is this a worry if we go much beyond it? I see the 360 hp models give you another 1500 lbs gvwr and of course have the 10000 lb hitch. Is there anything else different on those with the 360 hp that really makes a difference for the added capacity -- different specs on brakes, air suspension system, chassis etc?
I would guess they could the same except for engine hp?
I like the fuel economy of our 340 hp and at almost 28,000 lbs it pulls and rides fine except is a little slow on steep hills. If the only real difference between having the bigger engine is being able to charge faster up hills then I wouldnt be so worried about being at or a little above my 28,000 lb rating and it would be a bummer if it was illegal to be over by any amount. We also plan to tow a 4000 lb Honda CRV sometimes.
Is this GVWR weight issue a real worry?

[dimurrrw]

The only variable, other than the the 20 hp difference, seems to be the transmission.
Allison 2500MH vs Allison 3000MH.

Go to Forestriverinc.com/Berkshire and see both Specifications (340) and Options (360).

Gee, I wonder what a transmission rebuild costs for one of those things?

[klucas]

There is more than just 20 hp. The torque is quite a bit higher. Also has the better trans and aluminum wheels. I have the 360 in my coach. I added that as a option because I tow a van (4500 lbs)on a dolly. It raises the hitch capacity from 5000 lbs to 10000 lbs. tows like a dream. It doesn't search for gears much I would assume because of power. I usually run about 70 mph towing and get about 9-11mpg depending on hills and wind. Hope that info helps.

[mjracsj]

Thanks for the replies. So 20 hp and more torque plus the 3000 mh transmission are the only real differences. (of course the aluminum rims too but not related to gvwr so Im not counting them)
The 2500mh transmission obviously can handle the posted 33000 lb gross combined weight of coach + trailer for which it is rated so I wouldnt think it to be the limiting factor in keeping a coach with 340 hp and no trailer restricted to 28000 lbs. I am just trying to understand why the 360 hp is rated for 29500 for the coach (although I understand why the 360 hp has an extra 5000 lbs of combined coach + trailer weight rating and that makes sense)
Assuming the transmission temps are fine when I run fully loaded with my 340 hp then aside from just having to be in the slow lane on a few hills is the approx 1500lb difference in the gross vehicle weight ratings a big deal? Im not asking anyone to advocate running "overweight" over the 28000 lbs with the 340 motor but am wondering if it is really a big deal to be pushing the limit on it?

[klucas]

For me it was the old. I rather have it and not need it. Than need it and not have it. Having the extra power is nice. I don't worry about overloading etc.
Just load it fill the fresh water tank and go. It's all in your comfort zone.

[mjracsj]

Thanks again for the thoughts. I too would rather have it and not need it as far as power but in this case I dont have it! Just struggling with what is actually doable and not necessarily illegal (is gvwr a legal issue for non commercial vehicles or a "manufacturers advisory") and want to make sure we are legal and safe. In reality we are probably running 28500 fully loaded with only minnimal water and am worrying to the point of whether I should only run with little water and 1/2 full fuel tanks to be near the coach's posted 28000 gvwr - hard to determine when as far as fuel and water I'd also rather have it than need it. It just didnt make sense to me if it wasnt a transmission or suspension or braking issue to the point that my coach would be over 28000 but the tow vehicle would be well under 5000 and while still staying under the 33000 Gross Combined Weight Rating that somehow I would be better off unloading stuff from the coach and packing onto the towed vehicle. That logic is what made me question whether the 28000 is really a limit when I have no toad (especially if the higher rating for the coach equipped with the 360 hp has the same air ride, chassis and brakes) - If I could spend $10,000 today to upgrade to the 360hp I would but am stuck with what I have and if Im not taxing the coach suspension, transmission and brakes running the 340hp at 29000 lbs with no toad (when it is rated for 33000 combined) then am I really hurting anything other than being the slow vehicle on hills but dont feel anything anywhere else?

[Superchief]

Mjracsj,

I "struggle" with the same issue that you have about weight. I also have a 2011, with the same HP and Tranny. I also pull a 2011 Honda CRV. My unit is a 390 BH. I have traveled over 7000 miles since my purchase last August and I have never had any problems or issue with power going up hills. I have traveled a lot through the West Virginia area and in the North Carolina "gap" area. Never wished I had more power available, didn't need it. As for weight, I was really surprised the first time I had it weighted. I didn't think I had a lot of weight on board, but I was over weight. I ended up offloading the fresh water I had on board in an attempt to get under weight, so I could get the proper pressure in the tires. I reweighed the Coach today. Front is 340 lbs under Max of 10500 (10160) and back is 200 lbs over Max of 17500 (17700). I should be okay as my fresh water tank is about 1/3 full. Gray and Black are empty. Need to reduce fresh water tank again. I am full with diesel and DEF and loaded out basically. My total max weight is suppose to be 28000 and right now I sit at 27860, not much room left. I have also thought of doing what you mentioned of moving stuff from the unit to the Toad. I also monitor the temperature in the tires and I have not seen any excessive temperature issues. My mind set (right or wrong), is that the max weight of 28000 lbs is a conservative estimate on their part, and I will be safe within an acceptable range. I don't know what that range is, but I am being conservative in how much I exceed it. I am interested in yours and others thoughts.

Craig

[Herk7769]

Originally Posted by Superchief

My mind set (right or wrong), is that the max weight of 28000 lbs is a conservative estimate on their part, and I will be safe within an acceptable range.

Craig,

With the competition to post the highest capabilities possible for every vehicle used for towing and hauling out there, my feeling is they may "slightly" overstate rather than understate their weight numbers.

By incorporating an "expected useful life till failure" in their numbers they can increase stated capability without increasing metal.

I have no "basis in fact", to feel this way; but it is used in aviation designed limits (speed limits, G Loading, max and min takeoff/landing weights, takeoff and landing cycles, etc). Only by saying "What do I expect it "to do" before it fails and yet last 10 years," can you find limits.

If an aircraft's "useful life" needs to be extended, the design engineers go through every longeron and strut with an NDI (non-destructive Inspection) team X-Raying and Magnefluxing everything to determine what need replacing. This is called a SLEP. Service Life Extension Program. Anything close to failure needs to be replaced and even THEN they get it wrong and there is a wing or fuselage failure without warning. (You may remember the C-130 fire fighting aircraft some years ago). I see no reason that truck/car engineers would be trained differently.

Fighting Fire with Fire - YouTube

If you exceed the maximum stated capability you will shorten the useful life of your vehicle. Depending on the degree you exceed it; the length of time it is exceeded (or both); it can seriously degrade it's useful life.

[mjracsj]

Could it also be a little bit of marketing mixed in to make the upsell to the 360 hp more attractive? Yes I know it has the heavier capacity hitch which makes sense for it to have a greater combined coach + towed vehicle capacity with its higher horsepower but if it has the same rubber for tires and same brakes then why else the difference (about 1500 lbs) for its rated gvw for the coach only? Yes I do wish I had the bigger engine and would have spent the money but it wasnt available on the "in stock" 2011 holdover in which I was able to work a deal for the dealer to take a crazy trade in (a big boat) so I went with what I could get thinking I could live without the bigger hp figuring I was getting the same heavy duty DP coach otherwise. I have had no issues and love it but was surprised how quickly it reached the upper end of the weight rating. I wonder how much some options it came with weigh like the baggage compartment slide out tray? Given that my coach empty weight is a good bit more than stated in the literature I seem to have less cargo capacity than I expected.
My plan I guess is to keep the water level at a minnimum and since we usually travel not much more than 4 hours away I dont need to keep 100 gallons of fuel in the tanks. I can live with keeping fuel at around half full if needed.
I am a bit new to this and thank everyone for their thoughts.