Towing a Momentum 395ms

[BobKilmer]

I just purchased a grand design 395ms. I had purchased a 2022 diesel Chevy 3500 4x4 SRW long bed for a tow vehicle prior to buying the trailer, but I am starting to get nervous if it can handle the trailer. I’m still waiting on the truck to come in and may be able to switch to a DRW at the same dealership. I’d like to have a SRW over DRW but can the SRW actually pull this trailer? I have been told by 4 separate salesmen it could but not sure if they were just trying to get me to buy. I will not actually be hauling a toy but converting it to a kids room and living in the rig full time. Thanks.

Rauser64,
Rather than just jump to the recommendation of switching to a dually I would like to give you some information and let you decide.

Since you have the long bed SRW truck, your Gross Vehicle Weight Rating (GVWR) is either 11,900 pounds or 12,250 pounds depending on if you have 2WD or 4WD. I am guessing this gives you around 4,000 pounds of payload, depending on the configuration of the truck. The exact information is on your driver's side door jamb.

With a 4,000 pound payload, you would have about 1,100 pounds of excess payload capability for an empty 395M. If I use the rule of thumb that 20% of the cargo you carry goes into the pin weight, then the available cargo capacity of 4,400 pounds for a full 395M would result in a pin weight increase of 880 pounds. This would leave you just 220 pounds for carrying your kids, the fifth wheel hitch, cargo in the truck, and any additional weight for you are/or your wife that is over 150 pounds each.

On the surface this looks bad, but the reality of a toy hauler is that the weight you put in the garage actually reduces the pin weight, since it is behind the axles. This means that 20% rule of thumb I used above depends quite a bit on where the cargo is loaded. For my 381M, if I put 1,000 pounds in the garage the pin weight goes DOWN by 400 pounds. The result is I never get close to the 20% rule of thumb and actually have more issues with too little pin weight than too much pin weight. If you look around this forum you will see many others who have this same issue. If you install a washer/dryer in the garage and have the optional 1/2 bath, those are going to further decrease the pin weight, as will all the items you add to turn the garage into a kids room.

The net of the above is I would guess that once you have everything loaded in the RV and the truck, you may be under the SRW truck payload. Unfortunately, you wouldn't know that for sure until you had everything loaded and weighed the configuration. You may then also run into a rear axle weight limit, even if you are under the total truck payload. If you want more accurate estimates, please feel free to send me the numbers for your particular truck and I can provide you better inputs for your decision.

[MyRVRadio]

We have a dually for our 399TH, but I have seen plenty of people using an SRW. Having said that, all the arguments for stability *are something to consider*, but the numbers are the numbers. Focus on those first.

[ktnissen]

I tow a 2021 395MS-R. Years of experience towing RVs short stunt as a truck driver and years of military driving. I will tow our 395 with nothing less than a dually. What everybody says about you can with a SWR is true. Not that it makes a bit of difference getting across Oklahoma with 50 mph gusts, or trying to slow yourself down coming in to Jackson. I invested a lot of money and time for this lifestyle, why short change. I don't work off the bottom half, fuel tank, insurance or the tools to haul a beast of a toy hauler

[Spartacus]

Every configuration is different and you can't tell what is required without knowing the details. There are those of us who tow a toyhauler with a SRW and are within all our towing limits, verified by CAT scales. I now have over 20,000 towing miles in this configuration. I just left Windrock Park with my 381M, 10 degree slope going in and out. My SRW did great.

Roger that.

[Overtaxed]

I tow a 2021 395MS-R. Years of experience towing RVs short stunt as a truck driver and years of military driving. I will tow our 395 with nothing less than a dually. What everybody says about you can with a SWR is true. Not that it makes a bit of difference getting across Oklahoma with 50 mph gusts, or trying to slow yourself down coming in to Jackson. I invested a lot of money and time for this lifestyle, why short change. I don't work off the bottom half, fuel tank, insurance or the tools to haul a beast of a toy hauler

Perfect conditions, I'd tow a 395 with a F150. At 20MPH. But I'd do it if I absolutely had to, and, so long as the tires didn't let go, it would probably be "fine".

Think of a diagram with road conditions, speed, wind, rain/snow, etc on one side and trucks on the other side. A line across showing where you can control the load well for the conditions described. Flat ground, 60 degrees, sunny, no traffic, smooth road, slow speeds, no wind.. You could tow a 395 with a beefed up golf cart. 50mph wind, snow, hilly, bumper to bumper traffic; I wouldn't do that in anything less than a semi (with chains).

The question isn't really "can I tow it", that's easy, the answer is almost always yes. The question is, can I tow it safely given the road/weather conditions. A dually is going to be a yes in many of those cases where a SRW will be a no.

If you can be very selective about where you go and when you go so you can avoid difficult situations, I'm sure most people would be fine with a SRW. If you want to tow when you want to go, well, that's where things get dicey. You can do it safely with a DRW in a lot of situations where a SRW would be a "heck no". And most people fall into that 2nd category, they tow it when they need to tow it, not when the weather and conditions are perfect.

The real kill shot for me on my brand new F250 (which I traded for an F450, had about 5000 miles on the clock when I traded it in; yes, that hurt) was a member talking through the above with me. And, except for the short term pain in the wallet, I'm happy that I made the change. I'm 99% sure I would have gotten everywhere I wanted to go with my 250; but, at the same time, I'm sure some of them would have been far more damaging to my steering wheel as I white knuckled my way through it.

Finally, another argument that was made that resonated with me, and is absolutely true having owned a 250 and 450 back to back; the 450 tows better. It tows better on a sunny day without wind on a smooth road, and it tows better in terrible conditions. It's a much more stable, controlled, and "relaxing" experience towing with a dually, even when you're entirely within the specs of both trucks, the dually is still noticeably to very significantly better. I have a small 7K landscape trailer that I towed with my F150, F250 and now F450. The F450 tows that trailer so nicely that you can literally forget it's back there. The F150 would surge and get kicked around. The 250 was much better than the 150, but the 450 is even better still. Long way of saying, even if you don't "need it", a dually still provides comfort, safety and control when you're towing.

Which is a very good thing. DRW pick up truck exist for one reason, towing. If they weren't really good at it, they would be expensive SRW trucks that you can't use in a drive through or park easily. There is a reason they exist, and a reason people buy them; they are better towing platforms, full stop, compared to SRW. And they give you a lot more margin for something to go wrong and wind up sitting waiting for AA vs in an accident.

[spencers45]

Great answer, xrated

[BobKilmer]

Perfect conditions, I'd tow a 395 with a F150. At 20MPH. But I'd do it if I absolutely had to, and, so long as the tires didn't let go, it would probably be "fine".

Think of a diagram with road conditions, speed, wind, rain/snow, etc on one side and trucks on the other side. A line across showing where you can control the load well for the conditions described. Flat ground, 60 degrees, sunny, no traffic, smooth road, slow speeds, no wind.. You could tow a 395 with a beefed up golf cart. 50mph wind, snow, hilly, bumper to bumper traffic; I wouldn't do that in anything less than a semi (with chains).

The question isn't really "can I tow it", that's easy, the answer is almost always yes. The question is, can I tow it safely given the road/weather conditions. A dually is going to be a yes in many of those cases where a SRW will be a no.

If you can be very selective about where you go and when you go so you can avoid difficult situations, I'm sure most people would be fine with a SRW. If you want to tow when you want to go, well, that's where things get dicey. You can do it safely with a DRW in a lot of situations where a SRW would be a "heck no". And most people fall into that 2nd category, they tow it when they need to tow it, not when the weather and conditions are perfect.

The real kill shot for me on my brand new F250 (which I traded for an F450, had about 5000 miles on the clock when I traded it in; yes, that hurt) was a member talking through the above with me. And, except for the short term pain in the wallet, I'm happy that I made the change. I'm 99% sure I would have gotten everywhere I wanted to go with my 250; but, at the same time, I'm sure some of them would have been far more damaging to my steering wheel as I white knuckled my way through it.

Finally, another argument that was made that resonated with me, and is absolutely true having owned a 250 and 450 back to back; the 450 tows better. It tows better on a sunny day without wind on a smooth road, and it tows better in terrible conditions. It's a much more stable, controlled, and "relaxing" experience towing with a dually, even when you're entirely within the specs of both trucks, the dually is still noticeably to very significantly better. I have a small 7K landscape trailer that I towed with my F150, F250 and now F450. The F450 tows that trailer so nicely that you can literally forget it's back there. The F150 would surge and get kicked around. The 250 was much better than the 150, but the 450 is even better still. Long way of saying, even if you don't "need it", a dually still provides comfort, safety and control when you're towing.

Which is a very good thing. DRW pick up truck exist for one reason, towing. If they weren't really good at it, they would be expensive SRW trucks that you can't use in a drive through or park easily. There is a reason they exist, and a reason people buy them; they are better towing platforms, full stop, compared to SRW. And they give you a lot more margin for something to go wrong and wind up sitting waiting for AA vs in an accident.

This discussion is going further and further from the original question by the OP.

There is no such thing as roads that are only acceptable for a DRW truck versus an in-spec SRW truck. And people like me don't plan to travel only on perfect roads and sunny days. To believe that is to say that DRW truck owners know more than the engineers at SAE, DOT, and every major truck manufacturer. Engineers at those organizations spent countless hours of engineering time to determine towing tests, performance limits, speed limits, and vehicle designs so that the resulting vehicle configurations can safely operate on any public road.

Having a DRW drive truck doesn't give you the ability to go anywhere anytime under any conditions. Regardless of DRW or SRW configuration, in a battle between a 4 ton truck and a 9-10 ton trailer the trailer wins every time. Safe towing is more about having a properly configured trailer and using it under the proper conditions than whether you have a DRW or SRW. A 25 mph wind gust into a 40 foot fifth wheel only places about 185 pounds of force on the truck. An in-spec SRW truck can easily handle that. Move the wind up to 50 mph and the force is 740 pounds, still acceptable. At some point all the tractor trailers will wait until conditions improve and so should all RV owners.

[Overtaxed]

And people like me don't plan to travel only on perfect roads and sunny days. To believe that is to say that DRW truck owners know more than the engineers at SAE, DOT, and every major truck manufacturer. Engineers at those organizations spent countless hours of engineering time to determine towing tests, performance limits, speed limits, and vehicle designs so that the resulting vehicle configurations can safely operate on any public road.

Maybe look at it this way. There are conditions where a DRW truck will be able to tow safely and/or avoid an accident that a SRW truck will not. An easy example is a rear tire blowout at speed, on a DRW that would be a scary few moments, on a SRW, it could be the last few moments.

Having a DRW drive truck doesn't give you the ability to go anywhere anytime under any conditions.

I didn't say that it did, nor would I imply that anyone should look at it that way. I would say that a DRW gives you more margin in all conditions, and, in marginal conditions, you're going to really start to see the difference between the two. One of my first tows with the F450 was through some absolutely "lovely" weather; rain, wind, a little dusting of snow. It was awful. And I was really, really happy that I was in that truck. And I would have been even happier in a semi, I'm sure, because, like going for a F250 to 450, going from an 450 to a semi buys even more margin and safety.

The worst thing in my SRW truck wasn't actually wind, it was off camber downhills where the trailer would try to push the end of the truck around. Coming down a steep hill, slowing down and trying to go around a sharp curve. It was just squirrely, nothing ever happened, and perhaps with experience, I would have gotten used to it. But it's obvious that type of situation, because you have so much more contact patch, a DRW is going to be better, and, unsurprisingly, it is.

I'm well aware the logical conclusion of my line of thought is that everyone should have a semi to tow a 2K Harbor Freight trailer. But the thought is correct, the more weight, the more tires you have on the TV, the more control you will have. I noticed it on the RV, and I notice it on my little 7K landscape trailer. I towed that 7K trailer with a F150, F250 and F450, all well within spec for a trailer of that size (nothing overloaded) but it's immediately obvious how much better each step up towed that little trailer.

The question that the OP asked is easy to answer, can a SRW tow it? Yes, it can. Can it do it legally? Maybe, if you load very carefully and have a pretty stripped down truck in the 350/3500 class. Can it do it safely? Well, here's where we need to define terms. Can it do it as safely as a DRW? No, not assuming both are modern, well maintained trucks, and both are driven responsibly, the SRW will not be as safe as a DRW (which will not be as safe as a semi). Can it do it for 10s or 100's of thousands of miles without incident? On average, I suspect it can. I see people doing it all the time, triple axle trailers behind 250 class vehicles, and I'm still yet to see my first rear tire failure/trailer rollover incident. But I'd bet my life, whatever the mean time between serious accidents is on a SRW truck towing a heavy 5er, that same mean time is much higher on a dually.

[BobKilmer]

For the blowout discussion, all DRW trucks have single front tires. If the engineers who built those trucks felt that was acceptable, then I am OK with having single rear tires. Modern tires when properly maintained don't have blowouts. If they are damaged by road hazards they tend to go flat slowly, giving ample time to take the required actions. I experienced this personally last year while towing a utility trailer.

Another way to look at it is that a DRW design actually has a 50% higher likelihood to have a flat, since there are 50% more tires

For margin, you will notice I always say "in-spec" configuration. The issue that you describe is one of the stability tests run in SAE J2807, measuring understeer/oversteer and accelerations at the front end. The link below gives a nice summary of the "total control" tests:

https://www.motortrend.com/how-to/15...-the-standard/

As the article notes, these tests are designed to make sure the truck is not driven by the trailer at the maximum trailer weight.

I agree with your summary. Hopefully by now we have not totally confused the OP and made him cancel his RV and truck order.

[A.Texas.Yankee]

Eh, listen. I get the "I can do it" machismo and that's well and dandy, but...

For the blowout discussion, all DRW trucks have single front tires. If the engineers who built those trucks felt that was acceptable, then I am OK with having single rear tires.

Steer tires are singles for several major reasons and none of them weight related. If two wheels turned as well as one, with same vehicle width allowed by DOT, you'd see DFW on class 8 OTR as a standard and bigger Detroit diesels in lighter class trucks. Engineers build within the specs they are given by the company they work for, a company which has legal bounds it is trying to push as close to as possible.

Modern tires when properly maintained don't have blowouts. If they are damaged by road hazards they tend to go flat slowly, giving ample time to take the required actions. I experienced this personally last year while towing a utility trailer.

While modern tires are better engineered than ever before, to say they just don't have blowouts is inaccurate. Yes, poorly maintained tires are certainly more likely to have catastrophic failures, but even brand new tires can (and do) fail even when properly maintained. And road hazards don't always cause a slow leak providing ample time to make it to safety.

Another way to look at it is that a DRW design actually has a 50% higher likelihood to have a flat, since there are 50% more tires

Not an accurate statement unless you're merely referring to likelihood of surface area and running over something (even then...). There are far more factors in play and I can confidently say that failure rate of DRW is likely no where near 50% more than SRW. If this were even remotely true, the class 3 light duty truck market would look different, tire wise.

For margin, you will notice I always say "in-spec" configuration. The issue that you describe is one of the stability tests run in SAE J2807, measuring understeer/oversteer and accelerations at the front end.... As the article notes, these tests are designed to make sure the truck is not driven by the trailer at the maximum trailer weight.

That article fails to mention anything to do with payload nor length and height of trailer, load or trailer type, etc. Those are huge variables and arguably the most important. Also the stopping test is 20mph to 0mph and gives the truck 80ft to do it.

There are plenty of people that tow large, heavy trailers with a SRW truck and are within "range of specs" and most will not have an issue. But to even think for a moment that your SRW will stop a 20,000 lb, 45' long, 13.5' high trailer just as well as a DRW like a F350 dually or handle wind gusts just as well is just silly. A DRW is going to be more forgiving and more capable of providing a safer trip than a SRW in any real life situation (except maybe turning radius). If they didn't and it was all about engine and gearing, Class 8 HDT tractors wouldn't exist...

There's legal, and there's safer. Two completely different things.



Full-time Traveling Family ,'21 Momentum 395MS-R, '21 F450 King, 2000watts solar, Dual Victron MP-II 12/3000 2 x 120v, 1220ah LiFePo4