When we bought our F350, the sales person guaranteed that we would have at least a 3,600 lb cargo capacity. He said it should be closer to 4,000 lbs. We were not talking to some random Ford car salesperson; we were talking to one of the commercial truck sales people. You would expect them to know or companies would stop buying trucks from them. We learned that even the “smart” sales people have no idea what they are talking about.

Our truck was ordered during COVID while vehicle manufacturing was impacted by supply chain shortages, and it was a three to four month wait to get a vehicle. When our truck arrived, it had a 3,139 lb cargo capacity. When we pointed this out, the sales person said, “Huh, you do not have to buy it. There are no weird options on it, so we could probably sell it to someone else today.” There was no, “Oops, sorry. Is there anything we can do?” Sales people suck, especially, car sales people.

It often takes a few years for us to find a new RV that meets our needs, so we have started looking again. (Technically, we never stop looking. We check the available options every year just in case they start giving them away for free.) The trend has been to RVs to get longer, heavier, and more flimsy. I mean, this XLR Nitro 40BAR13 toy hauler has a 21,000 lb max weight, and it is more than 45 feet long. Custom RVs can be even heavier. Sadly, the style that we liked started at 36′ to 38′ with a 14,000 lb max weight in in 2019, when we started looking at 5th wheel RVs. They have grown in length over the years, so it is hard to find that style less than 40′ long, under a 16,000 lb max weight, and with sufficient cargo capacity.

This means that it is also time to start looking at trucks, too. If our current truck was not under capacity due to vendor ignorance, we might not have this issue. I say might not because there are many rating limits for the various parts in the truck. For example, we could be below the gross vehicle weight rating (GVWR), below the cargo carrying capacity (CCC), and at the limit for the gross axle weight rating (GAWR).

This happens to be the concern for our current truck with the current viable campers. If we bought an RV with our current truck, we might have to be at 90% or more of the rear gross axle weight rating, gross vehicle weight rating, tow capacity, and RV payload capacity. The vehicles should have a safety margin built into their specification, but it is safer to have a larger safety margin.

You might be wondering what the difference is between the F150, F250, F350, and F450. Just so you know, the difference is the number after the ‘F’. (Womp! Womp!)

• F150 – This is not a Super-duty truck. I guess it is just a duty truck? It only comes with a gas engine and single rear wheels (SRW). It has vastly lower towing and cargo ratings than the other three.
• F250 – This is the lowest of the Super-duty trucks. It bridges between F150 and F350. It is only produced with a single rear wheel (SRW), but it can be ordered with a gas or diesel engine. It is heavier duty than the F150, but you need to add features to bring the suspension and axle up near the F350 and F450 range.
• F350 – This is the bridge between F250 and F450. The default axle and suspension are stronger. It can be ordered with a single rear wheel (SRW) or dual rear wheel (DRW) and gas or diesel engine. The F350 is the super duty that can be configured with the highest cargo capacity.
• F450 – This is the hauling king; the only axle ratio is a 4.30 towing axle. It only comes with a diesel engine, DRW, and best towing axle ratio. It has a slightly lower cargo capacity than the F350, but it configurations with significantly higher gross combined weight rating (i.e., truck, cargo, and trailer). It can have the highest axle ratings of any of the non-commercial chassis.

You can go to commercial chassis to go beyond 14,000 lb gross vehicle weight ratings. This is where you hit the F550 and beyond.

This post, here, has information on how to calculate safe towing weights.

The Ford Motor Company source material has been copied to our site, for now. These (and the ford vehicle configuration webpage) are the references used for decision making. The pdf versions may download a file, so delete the downloaded file when you are done with it.

Document	Ford Link	Our Link
2026 Towing Guide	pdf	pdf
2026 Super Duty Specs	html	html
2026 RV & Trailer Guide	pdf	pdf
Ford Super Duty Build and Price	html	N/A

We have narrowed down the primary options.

• F350 or F450 – for the high gross vehicle weight rating of the RVs that are interesting, the F150 and F250 do not have enough towing or payload capacity. The F550 does, but we do not need commercial tow capacities.
• Crew cab – for room for the cats, liter pan, tools, and Kate, if needed.
• 8′ bed – for greater stability, storing leveling boards, and greater cab clearance for turning. (It is required for dual rear wheels.)
• Diesel 6.7L engine – for Hp/torque towing the RV up mountain roads
• Dual rear wheels (DRW) – for the additional cargo capacity and gross axle weight rating for the rear axle
• Four wheel drive (4x) – for muddy campgrounds

From what we can tell, the “High Output” diesel engine does not sufficiently improve engine power to be worth it. The crew cab and 4×4 option reduce the cargo capacity by about 1,000 lbs and 400 lbs, respectively. We expect the cargo capacity to be at least 1,000 lbs higher than our current truck, which will absorb the additional hitch weight of a heavier RV. We also have some secondary features that we have narrowed down.

• Definitely
  • 48 gallon diesel tank
  • Side of the bed step
  • Tailgate step
  • Skid plates
  • Bed lighting
  • Spray bed liner
  • Rubber flooring
• Maybe
  • XLT base package
  • 12,000 lb winch
  • Upfitter switches
  • Camper package (for max cargo rating)

The 2026 models use the same engine as the 2022 model. It is a 6.7L V8 Power Stroke Turbo Diesel. It is rated for 475 hp @ 2,600 rpm and 1,050 lb-ft @ 1,600 rpm. The 2026 guide shows maxes over all configurations. This was missing from the 2022 guide, but estimates are shown where exact values are not available.

• For all 2022 configurations,
  • the max conventional tow capacity is 24,200 lbs.
  • the max 5th wheel tow capacity is 32,500 lbs.
  • the max gooseneck tow capacity is 37,000 lbs
  • the max cargo capacity is about 6,950 lbs (Note: max shown in a table is 6,556 lbs).
• For all 2026 configurations,
  • the max conventional tow capacity is 30,000 lbs.
  • the max 5th wheel tow capacity is 35,000 lbs.
  • the max gooseneck tow capacity is 38,600 lbs.
  • the max cargo capacity is 6,952 lbs (Note: max shown in a towing guide table is 6,558 lbs. Max shown in the specification html is 8,000 lbs).

They have increased the ratings, but even the max 2022 ratings are well beyond what we need.

The relevant maximum ratings are show below. Some ratings are reduced by adding the weight of options or require certain options to increase them. Not all axle ratios are available for all vehicle configuration. A smaller axle ratio is better for gas mileage, and a higher axle ratio is better for towing.

Note: All three trucks are Ford Super Duty Crew Cab 8′ bed DRW with XLT trim.

Rating	2022 F350 SRW	2026 F350 XLT DRW	2026 F450 XLT DRW
Axle Ratio	3.55	4.10	4.30
Gross Combined Weight Rating	30,000#	43,900#	43,500#
Conventional Max Towing	20,000#	27,000#	30,000#
5th Wheel Max Towing	19,000#	35,000#	32,000#
Gooseneck Max Towing	20,700#	35,300#	33,000#

Rating	2022 F350 SRW	2026 F350 DRW	2026 F450 DRW
Axle Ratio	3.31	3.55	N/A
Gross Combined Weight Rating	30,000#	40,000#	N/A
Conventional Max Towing	20,000#	27,000#	N/A
5th Wheel Max Towing	19,000#	31,200#	N/A
Gooseneck Max Towing	20,700#	31,400#	N/A

Rating	2022 F350 SRW	2026 F350 DRW	2026 F450 DRW
Base Curb Weight	7,700# (7,500# – 7,800#)	8,070#	8,612#
Gross Vehicle Weight Rating	11,400# (12,400#)	14,000# (15,500#)	14,000# (15,500#)
Front Gross Axle Weight Rating	5,600#	5,600#*	5,600#*
Rear Gross Axle Weight Rating	6,780#	9,900#*	9,900#*
Max Payload Rating	3651# (2,751#)	5,030#	4,488#
Hitch Receiver Max	21,200#	28,000#	30,000#
Max Tongue Load	2,120#	2,800#	3,000#
Max Tailgate Height	56.7″-59.7″	58.0″-59.7″	58.6″-60.3″

You might be confused by the lower towing capacity of the F450 versus the F350, but it depends on the configuration. The highest towing capacity of any F350 is 38,000 lbs, and the highest towing capacity of any F450 is 40,000 lbs. These maximums are for regular cab 4×2 with the high output diesel engine.

The build specification lists max payloads that are about 900 lbs higher than the pdf towing guide. This might be the build specification allowing for deleting the pickup bed, which is not shown in the towing guide. (Note: This is probably 6 x 150 lbs = 900 lbs passenger weight.)

Assuming a similar curb weight of 7,700 lbs for our 2022 F350 SRW, the final weight is about 8,600 lbs, so about 900 lbs of driver, cargo, and options. The cargo is about 550 lbs (a 225 lb driver, 100 lbs of leveler boards, 75 lbs of tools, a 125 lb hitch, and 25 lbs of cats). For estimating, we will assume that the options weigh 450 lbs and cargo each weigh 550 lbs, for a total of 1,000 lbs. Unless the weight is concentrated in one place, the divide should not matter a great deal, as long as the weight is added to the curb weight.

We are looking at about a 18,000 lbs RV at the top end, which means a rough max of 3,600 lbs of tongue weight for a 5th wheel or gooseneck hitch. (A 15,000 lb to 17,000 lb actual RV weight is more likely.) The option estimates for the 16,000 lb and 17,500 lb RV are based on our research of the Brinkley Z3210 and Z3515. The RV cargo estimate is based on current RV weight readings, which include several hundred pounds of modifications that may not be needed with new RVs.

Using the F350 14,000 lb GVWR minus 5,000 lb cargo capacity gives a minimum curb weight of about 9,000. Using the F450 14,000 lb GVWR minus 4,500 lb cargo capacity gives a minimum curb weight of about 9,500. This value was about 1,000 lbs higher than the specifications that I later found. (Note: this is likely the 900 lbs of passengers mentioned later.) This suggests that either the curb weight or payload maximum value is low. These specifications also indicate that the max front gross axle weight rating (GAWR) is 5,600 lbs and rear GAWR is 9,900 lbs. Internet searches suggest that you can get higher rated axles. It will reduce the available payload, but increase the overall safety margin. The weight on the front axle of our 2022 truck is about 5,100 lbs, even when the weight of the RV changes. The new trucks are likely in the same range, since the front axle rating is the same.

Using the assumptions above for options and cargo for the truck and RV, the following shows the estimated weights of the trucks and RVs. (Note: a gooseneck hitch might remove about 100 lbs of cargo weight from the rear axle.)

Name	F350	F450	15,995 lb RV	17,495 lb RV	18,000 lb Max
Base Curb Weight	8,070#	8,612#	12,871#	13,989#	15,250#
Options	450#	450#	400#	500#	600#
Cargo	550#	550#	2,150#	2150#	2150#
Gross Vehicle Weight	9,070#	9,612#	15,421#	16,639#	18,000#
Front Gross Axle Weight	5,100#	5,100#	N/A	N/A	N/A
Rear Gross Axle Weight	3,970#	4,512#	N/A	N/A	N/A
Max Payload Capacity	5,480#	4,938#	2,724#	3,006#	2,150#
Payload Capacity Remaining	4,930#	4,388#	574#	856#	0#

A gooseneck and 5th wheel hitch should be 15%-25% of the loaded RV weight. Ours are typically pretty close to 20%, so the hitch weight will be 20% of the gross vehicle weight of the RV. In the table below, the gross axle weight of the RV is the remaining 80% of the weight on the tires instead of the hitch.

Name	F350 Rating	F450 Rating	16,000 lb RV	17,500 lb RV	18,000 lb Max
Hitch Weight / Rating	5,000#	5,000#	3,085#	3,328#	3,600#
RV Gross Axle Weight	N/A	N/A	12,336#	13,311#	14,400#
Front Gross Axle Weight /Rating	5,600#	5,600#	5100#	5100#	5,100#
Rear Gross Axle Weight /Rating	9,900#	9,900#	7,055# or 7,596#	7298# or 7840#	7,570# or 8,112#
Gross Vehicle Weight /Rating	14,000# (15,500#)	14,000# (15,500#)	12,155# or 12,696#	12,398# or 12,940#	12,670# or 13,212#
Gross Combined Weight Rating	43,900#	43,500#	24,491# or 25,032#	25,709# or 26,251#	27,070# or 27,612#
Maximum Gooseneck Tow Rating	35,300#	33,000#	15,421#	16,639#	18,000#
Maximum Payload Capacity	5,480#	4938#	3,635#	3,878#	4,150#

There is a discrepancy between the documentation about the payload capacity and base curb weight. That nearly 1,000 lbs could make the difference in the truck being able to safely tow an 18,000 lbs RV or not. The Ford truck configuration tool claims that the base curb weight of an F350 with XLT trim is 8,070 lbs with a max payload capacity of 5,930. The truck guide has a note about passengers being excluded from the payload weight, which is 6 x 150 lbs = 900 lbs. It lists a max payload capacity of 5030. It is highly probable that the 900 lbs difference is the passengers.

There is still a slight discrepancy in that the XLT specs page indicates a max payload for the F350 as 5,865 lbs. A max payload capacity of 5,930 lbs vs 5,865 lbs is not going to prevent these RVs from being safe. We will need to see some actual vehicle safety decals to verify this.

Generally the heaviest towed RVs are not more than 25,000 lbs, so the F350 has more than enough towing capacity to handle a 16,000-18,000 lb RV. The greater concern is the rear gross axle weight rating and payload capacity. Using the the F350 with higher payload capacity seems more useful than getting an F450, but we need to do some more research and ask “experts”.