Momentum -G vs -M class 5th Wheels

[LMychajluk]

I'm currently comparing the 350G to the 349M, and am wondering what the differences are in the construction?

What I'm seeing so far (edits added as they're pointed out):
- 12" Frame on the -M (not mention on the -G)
- Weather-Tek package on the -M (vs. 'Insulation Package' on the -G)
--- R45 Main floor on the -M vs R40 on -G
--- 'Rail-Tite' Underbelly Seal on the -M (no mention on -G)
- 8k Axle / Disc Brake option on the -M (also upgrades GVWR?)
- 'Tuf-Ply' Garage Floor on the -M (not mention on the -G)
- Triple Insulated Garage Floor on the -M (not mention on the -G)
- One Control on the -M
- 4-step Fold Up Stair on the -M
- 2 x 30 gallon fuel tanks on the -M (vs 1 on the -G)
- Frameless Windows on the -M (not mention on the -G)
- Central Vac on the -M
- MORryde® CRE3000 Suspension System on the -M (not mention on the -G)
- MORryde Pinbox only on the TH series (not on the -G or -M)
- Roller Shades on -M (partially? Not mention on the -G)
- Hydraulic leveling on -M, electric on -G
- Full Body Paint available on -M

I'm primarily interested in items that aren't easily upgradable later, but what else am I missing when comparing the -M to the -G class? Will it be worth it to spend the extra money on the -M now?

If I'm wrong on any of the above, or if you have anything to add, please let me know! Thanks!

BTW, if anyone from GD is reading this - the brochures / website are very unclear as to which options are included in 'which' of the 3 Momentum classes (Momentum, Momentum -M, Momentum -G).

[DarylB]

- M uses hydraulic for leveling and main slides, G has electric leveling system
- MORryde pin box is only on the TH models
- Dual pane windows available on M
- Full body paint available on M

I wish they would have been honest with me about the upcoming disc brake option when we ordered our 2020 381M in Jan 2020, I ask about it and the GD reps told me it would never happen on the Momentums, 3 months later it was available

[LMychajluk]

Thanks, DarylB - I'll update my OP above with your info.

But, both the -G and -M class list dual pane windows as options (as per the current web site), so I'll leave that off for now.

I did know about the hydraulic leveling, but forgot to add that to my list.

With the 8k Axles and disc brakes, I'm assuming the brakes are on all 4 wheels? Seems like an expensive 'upgrade' (unless they're also giving you the original 7k axles as spares?).

BTW, I actually prefer the layout of the 351M like you have, with the TV/Fireplace towards the rear, but more in front of the sofa. But, I need a little more length in the garage. There's the 381M, but that's getting into 3-axles already and >40'. I wish there was something in between w/ a ~13' garage and dual axles and the whole thing <40'. Basically, the 249M w/ the living area layout of the 351M...

[DarylB]

Maybe I'm wrong about the dual pane windows on the G

Disc brake option is on all wheels (4 or 6)

[LMychajluk]

Looks like the 'WeatherTek Arctic Insulation' increases insulation in the -M vs. the -G some...

G Class - https://www.granddesignrv.com/showro...l/construction
M Class - https://www.granddesignrv.com/showro...m/construction

- R45 Main floor on the -M vs R40 on -G
- 'Rail-Tite' Underbelly Seal on the -M (no mention on -G)

[Chuck.N]

Re: the 8k axles, my understanding from GD is that you're then limited by the pin box rating.

For example, our new M399th with 3 8k axles could theoretically handle 24k GVWR. Not so. The pin box is rated at 21k, so that's the max GVWR on the coach.

I searched around for 24k pin boxes, and no joy. That's not to say they're not out there. I just couldn't find one.

[LMychajluk]

Re: the 8k axles, my understanding from GD is that you're then limited by the pin box rating.

....

Makes sense.

OTOH, though, if you take one of the dual-axle -M class Momentums, you can upgrade to the 8k axles and, depending on whether they give you an 18k or 20k pinbox (not sure which is fitted), still add 1-2k# to the GVWR of the trailer. That's huge! W/o the 8k axles, for example, the 351M only has ~1,400# of CCC left after you fill the fresh water and fuel tanks (if my math is right) for some extended boondocking. That's doesn't leave much CCC for toys after you factor in your normal normal provisions and other cargo. The 349M does a bit better than the 351m, but it starts with 200# less UVW and has a 200# higher GVWR compared to the 351M. For comparison, the 350G still has ~2600# of CCC assuming the fresh water and fuel tanks are already full, even with the 7k axles.

From my limited research on it, what I don't quite understand is the cost of the upgrade. The $5k charge seems about right for a pair of axles, disc brakes, and related components (maybe a bit high?). But, the stock 7k axles and brakes aren't 'free' - doesn't it already cost a certain amount for the parts (maybe $2k?)? If you're substituting in a different set of parts, wouldn't there be an offset in price that's less than the full price of the 'upgrades'? I can't see the labor being much different to fit the axles...

[Chuck.N]

Yeah, you'd think there would be a credit for the standard axles. I bet there is, but it's dealer credit. When I asked my dealer about the 8k option, he quoted me about 50% off the GD price.

[LMychajluk]

Saw a pic posted of a 320G at a dealer earlier that had the 'Weather-Tek Arctic Insulation' sticker on a 320G, so now I'm wondering if there are really are any significant insulation differences between the -G and -M(?).

[MooManChu]

Saw a pic posted of a 320G at a dealer earlier that had the 'Weather-Tek Arctic Insulation' sticker on a 320G, so now I'm wondering if there are really are any significant insulation differences between the -G and -M(?).

Our 2020 320G has all these packages. There are other subtle differences not documented in the features between the G and M. Best to look at the trailers side by side. My best advice is to find the floorplan that works for you best regardless if it is an M or G.