Picking The Correct Size Tow Vehicle

[ThePearls]

My wife & I are looking to buy our first 5th wheel. I have done quite a bit of reading on the subject of how much truck is required to tow the various 5th wheels and there seems to be no shortage of different opinions. Many of the posts suggest that the only way to know for sure is to weigh the truck and camper. I would like to know BEFORE buying the truck.

We are looking at the Reflection 337RLS. I prefer the 303 but she "has" to have a washer/dryer. I've seen posts that say the pin weight of 337's can be in the 3100lb to 3200lb range which looks to me like a dually is required. I do not really want to get a dually but will if I absolutely have to.

The local camper dealer would not say if the 337 needs a dually. They just say, "We will not sell me a camper that I cannot safely tow". The dealer did give me a name at Grand Design to email. He was also non-committal about the need for a dually. I talked to the local Ford dealer and they seemed unaware of payload requirements. They just gave me a brochure that says the Ford Super Duty can tow up to 34,000lbs.

I found a 2017 F350 Lariat Diesel SRW SuperCab 4WD Long Bed on my local Ford dealer’s lot. The payload sticker said 3639 lbs.

I have read that the payload has already taken into account a 150lb driver + fuel. Using that assumption, I have calculated...

Payload on Door Sticker 3639
Less Hitch -250
Less Passengers -250
Less Extra Cargo -200

Remaining Payload 2939

Pin Weight of 337RLS -3200

Remaining Payload -261

In the signatures on this forum, I have noticed 337's with both SRW and DRW tow vehicles and I am wondering if the SRW folks might comment on
their decision on using SRW and being so close to the max specs of the truck. Do they regret getting a SRW and wish they had gotten a DRW?

I also plugged the numbers into the FifthWheelTruckTrailerCalculator spreadsheet, which I got from a link I found on this forum.

That spreadsheet says that the truck is capable of safely towing the 337RLS 5th wheel. The spreadsheet appears to be using Rear Axle Weight Rating and the Rear Tire Rating as the limiting factor instead of payload.

For the F350, the ratings are

Rear Axle Weight Rating = 7280 lbs.
Rear Tire Rating = 3750 lbs. x 2 tires

Is the payload secondary to Rear Axle Weight Rating and the Rear Tire Rating?

I have another weight related question. We are also looking at a 2nd AC and washer/dryer. That is around 300+ lbs. at the very front of the 5th wheel. Does that affect the percentage of the trailers weight that ends up as pin weight?

[TucsonJim]

A fully loaded 337 with a second AC, washer and dryer will certainly have a pretty heavy pin weight. My 2014 337 was right at the limit for my 2013 Ford F350 SRW's GAWR (Rear). And I was probably a little over on the payload. And I didn't have a washer/dryer in it. So you'll certainly be at or near the limit with a SRW. It will be interesting to see some owner's of newer units weigh in (pun intended).

Jim

[SouthTX]

My 337 pinweight is generally around 3150 and I'm not only well within all the ratings, but when I hit the CAT scale I have just under 1,000 cushion on the RAWR. (Mine is 7230)

I wouldn't want to go much bigger than a 337, but my '17 CCSB SRW 6.7 Lariat Ultimate pulls my 337 just fine (and within all ratings). For me, the bed height is a bigger problem than the weight, but replacing the rear axle blocks with those from a F250 solved the problem. I also have good cab clearance with no need for a slider using an AUH. The truck is super comfortable and we literally don't know the RV is behind us. I recommend disk brakes highly, though.

BTW, listen to your wife. Mine didn't want the W&D, but just liked the BR layout better. I think she was right. Hope you enjoy yours as much.

[Second Chance]

We previously pulled our 337 (3,000 - 3,200 lbs. pin weight depending) with a Sierra 2500HD D/A 2WD. Per scales loaded, the truck had 3,200 lbs. payload and, hitched up, we usually ran about 100 - 200 lbs. below the rear axle rating and had a bit more margin on the rear tires. With Timbrens and Bilstein shocks, it pulled and handled fine - I was just always a bit nervous about a rear tire failure on the truck with a SRW. When we had the chance to trade even for a good DRW truck, I jumped on in like a fly on... well, you get the idea.

Rob

[TheLexx]

Are you going to be filling your tanks with water before traveling? Water is heavy.

A number of posters have stated that DRW is a more stable tow FWIW.

[Second Chance]

Are you going to be filling your tanks with water before traveling? Water is heavy.

A number of posters have stated that DRW is a more stable tow FWIW.

The fresh water tank on a 337 is just over/behind the rear axle - doesn't add any weight to the pin. The waste water tanks (both gray tanks and the black tank) are between the front axle and pin, so they will add considerable weight to the pin. We always travel with the waste tanks empty when possible (1/4 full when using the "Geo method" to clean the tanks on a travel day). On travel days with predicted high winds (like in west Texas, New Mexico, Arizona, etc.), I always make sure the fresh tank is full for extra ballast down low.

Rob

[LCBoyer]

I feel much safer with a DRW truck because of the wider footprint.

[ThePearls]

Thank you all for your replies. I guess that even though a SRW can handle it, it's right at the limits and that a DRW would be the better choice.

[mtpocket]

Buy a truck big enough to pull this one fully loaded and more importantly, you're NEXT one fully loaded.

[TheLexx]

Buy a truck big enough to pull this one fully loaded and more importantly, you're NEXT one fully loaded.

That's what I did