User Tag List

Thanks Thanks:  0
Likes Likes:  0
Results 1 to 9 of 9
  1. #1
    Seasoned Camper
    Join Date
    Jun 2020
    Posts
    162
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    M399th Weight - Empty but "Wet"

    Soon to (hopefully) become the owner of a new M399th. I was wondering what the weight of the coach is without owner goods, but with full loads of water and propane (and maybe gasoline). Has anyone weighed in like this? I estimate that a full load of water, gasoline, and propane will weigh about 1,800#. If the dry weight is 15.9k, it will weigh about 17.7k "wet". Am I close?

    Maybe I'm unsure what GD is including in their UVW spec.

    I did a forum search, but came up blank. TIA
    Last edited by Chuck.N; 06-14-2020 at 11:39 AM. Reason: Clarification

  2. #2
    Paid my dues 😁 FT4NOW's Avatar
    Join Date
    Sep 2016
    Posts
    4,570
    Mentioned
    136 Post(s)
    Tagged
    0 Thread(s)
    Mine is a 2017 and if I recall it came from the factory around 16.7k or somewhere around there (I have dual pane windows, 3rd AC, super sofa, king mattress, generator). I only have the standard FW tank, not the aux, so calculate water accordingly (approx 8lbs per gallon) (GD doesnt include water as part of their factory weight anyway). The factory weight doesnt include battery or propane tanks. Hope that helps, I dont have my actual weight sheet handy at the moment.

    Sent from my SM-G950U using Tapatalk
    2023 Momentum 398M-R
    2023 Ford F-450

    SOLD - 2021 Reflection 311BHS
    SOLD - 2017 Momentum 399TH

  3. #3
    Site Team xrated's Avatar
    Join Date
    Feb 2019
    Location
    "Murvul", TN
    Posts
    3,359
    Mentioned
    135 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Chuck.N View Post
    Soon to (hopefully) become the owner of a new M399th. I was wondering what the weight of the coach is without owner goods, but with full loads of water and propane (and maybe gasoline). Has anyone weighed in like this? I estimate that a full load of water, gasoline, and propane will weigh about 1,800#. If the dry weight is 15.9k, it will weigh about 17.7k "wet". Am I close?

    Maybe I'm unsure what GD is including in their UVW spec.

    I did a forum search, but came up blank. TIA
    The UVW is the trailer as it leaves the assembly line. There are no battery(s), and there is no propane in the tanks (usually two 30 lb tanks). There is no water in the fresh tank, nothing in the gray or the black tank. So if you fill the fresh water tank completely, you are adding approx. 1300 lb worth of water (155 gallons time 8.34 lb per gallon. The battery and propane will put an addition 150 lbs or so, and the gasoline in both 30 gallon tanks will weigh approx. 380 lbs (6.3 lbs times 60 gallons) All of that totals up to around 1830 lbs. So if you add that weight total and the existing empty weight that is published, you are spot on at about 17,700 lbs. I'd say you nailed it as far as an approximation, but the true test is to go to the scales and get some weight tickets done.....then you will know exactly, and you will also know how much more "stuff" you can put in the trailer.....food, clothes, a toy in the garage, etc.
    2016 F350 CrewCab Dually
    2018 Momentum 394M...Heavily Modded!
    2023 Suzuki GSX-S1000 GT+
    Excessive Payload is a Wonderful Thing

    "If it ain't fast....It ain't Fun"

  4. #4
    Seasoned Camper
    Join Date
    Jun 2020
    Posts
    162
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks to all that replied. I'd like to take this a step further, if I may. I played around with some numbers, and if fully loaded with water, etc, plus the almost 1,400# of our "toy", we're left with only about 800# for personal stuff (clothing, pots, pans, etc.). That's troubling.

    So, we still have the option of upgrading to the 8k axles. Will these increase our maximum GVWR for the coach?

  5. #5
    Site Team xrated's Avatar
    Join Date
    Feb 2019
    Location
    "Murvul", TN
    Posts
    3,359
    Mentioned
    135 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Chuck.N View Post
    Thanks to all that replied. I'd like to take this a step further, if I may. I played around with some numbers, and if fully loaded with water, etc, plus the almost 1,400# of our "toy", we're left with only about 800# for personal stuff (clothing, pots, pans, etc.). That's troubling.

    So, we still have the option of upgrading to the 8k axles. Will these increase our maximum GVWR for the coach?
    I don't know about that. Yes, you would in theory, but the structural members of the trailer likely also play into the GVWR of the trailer....think main I beams, flooring construction, etc. That's probably a question for Grand Design and possibly where you have the work done.
    2016 F350 CrewCab Dually
    2018 Momentum 394M...Heavily Modded!
    2023 Suzuki GSX-S1000 GT+
    Excessive Payload is a Wonderful Thing

    "If it ain't fast....It ain't Fun"

  6. #6
    Site Sponsor Crazybanshee's Avatar
    Join Date
    Jan 2017
    Location
    Westminster,Co
    Posts
    148
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Your limiting factor is the pin box. Probably rated for 20K. Up grading the axles will not help that.
    2007 Volvo 780 VNL Trailersaver Hitch
    2017 Momentum 397th
    2015 Polaris RZR 900S Voodoo Blue
    2017 Polaris RZR S1000 Matte Black
    2019 Polaris RZR S1000 Titanium Matte
    3 Yamaha Banshee's 2-Honda 400 EX's
    Honda 250EX 2016 Polaris Outlaw 110 EFI

  7. #7
    Seasoned Camper
    Join Date
    Jun 2020
    Posts
    162
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Figures. I didn't think about that. I heard last night from GD that the 8k axles give me about 700# more GVW. I'll check on the pin box max today.

    So, how do you all do it? Am I just overthinking it? Those that haul larger OHVs, how do you manage weight if you're FT?

  8. #8
    Site Team xrated's Avatar
    Join Date
    Feb 2019
    Location
    "Murvul", TN
    Posts
    3,359
    Mentioned
    135 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Chuck.N View Post
    Figures. I didn't think about that. I heard last night from GD that the 8k axles give me about 700# more GVW. I'll check on the pin box max today.

    So, how do you all do it? Am I just overthinking it? Those that haul larger OHVs, how do you manage weight if you're FT?
    Chuck, I don't full time, so my trailer (Momentum 394 with a 20K GVWR just like yours) is not loaded enough to worry about the "extra" weight that you may encounter. As far as the pin box, mine has the 1621 HD on it and is rated at 21,000 lbs. I also chose to go with the B&W Companion hitch for it.....the 25K model vs. the 20K model. You may want to do a search on google and check out the website of Chad and Tara, who are Grand Design ambassadors. Their web site is "Changing Lanes" and they are definitely full time and have been for about 2 1/2 years. They have a 397 and if I'm not mistaken, Chad has talked about pin weights in the 4500 to maybe slightly higher range. They are 100% within all the weight ratings of both the trailer and the truck and many, many videos, including proper loading, setup, etc.....
    2016 F350 CrewCab Dually
    2018 Momentum 394M...Heavily Modded!
    2023 Suzuki GSX-S1000 GT+
    Excessive Payload is a Wonderful Thing

    "If it ain't fast....It ain't Fun"

  9. #9
    Seasoned Camper
    Join Date
    Jun 2020
    Posts
    162
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thank you sir! I'll give it a look. We're still searching hitches. Since our truck is a Ram Megacab Dually, we're looking at sliding hitches in the 21k+ range. I'm sure we'll eventually get there, and the search has been fun, but stressful. We want to get it right the first time.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

DISCLAIMER:This website is not affiliated with or endorsed by Grand Design RV, LLC or any of its affiliates. This is an independent site.