Buy a new 5th wheel, ripe project for a boat tail

[Hersbird]

So after looking into it more, it seems the SAE J-2807A towing tests are done with 60 sqft frontal aera box trailers. So they can't say with authority the trucks can tow the SAE J-2807A rated weight, up hills, in high temps, ect. unless your trailer also has less drag then a 60 sqft box trailer. I wouldn't really call that a limit but a consideration. Still doesn't mean Ford won't be jerks when it comes to warranty. How do they explain all the pictures in their ads and on the webpages of Ford trucks towing obviously over 60 sqft frontal trailers?

[aerohead]

Originally Posted by mwilliamshs

Sounds like the Max Trailer Towing Package. As long it has 3.73 gears (axle code 26, B6, or L6) it should be good for 11,300 lbs and 60 sq ft of frontal area so long as it has a 16,600 GCWR sticker in the door jamb. Keep in mind tow capacity is based on GCWR which is based on GVWR and that assumes an empty truck.

16,600 - 5,254 (Ford's published curb weight for 2014 4x2 3.5L F150 CrewCab) = 11,346. So in order to tow at maximum ratings the driver needs to weigh 46 lbs or less and drive an otherwise unloaded truck without accessories.

I have seen frontal area limitations used to deny warranty claims more than once, just fyi. More for automatic transmission failure than anything else but at least one rear axle failure as well.

John intentionally chose a lighter-than-maximum weight trailer for some safety factor.Perhaps it will help compensate for the extra aero load until he can get the CdA of the rig down to 60-sq-ft CdA territory.
It would be helpful if the EPA would select a reference tow vehicle and conduct quantitative evaluation (say,at the Transportation Research Center in Ohio )to create 'Manroney Stickers' for RVs,which include aerodynamic and rolling resistance data,along with gross weight.
We have 'em,in a way for vehicles.
They even have Home Efficiency Rating System (HERS) for home buyers.
I'd gladly pay federal taxes to support such public education.Otherwise,consumers will continue to be shackled to the 'Edsels' of RVs.

[aerohead]

Originally Posted by Hersbird

So after looking into it more, it seems the SAE J-2807A towing tests are done with 60 sqft frontal aera box trailers. So they can't say with authority the trucks can tow the SAE J-2807A rated weight, up hills, in high temps, ect. unless your trailer also has less drag then a 60 sqft box trailer. I wouldn't really call that a limit but a consideration. Still doesn't mean Ford won't be jerks when it comes to warranty. How do they explain all the pictures in their ads and on the webpages of Ford trucks towing obviously over 60 sqft frontal trailers?

It looks like the SAE has been conducting tow tests up the Davis Dam grade,or equivalent,since 2008.The trucks must maintain 40-mph,so even if aero was a criteria,it's impact would pale in contrast to that of climbing.It's got to handle the desert summer heat,with full AC blasting away.
Here's a link
That Dam Towing Test: New SAE Trailering Standards Explained - Tech Dept. - Car and Driver

[slowmover]

SAE J2807 is expressly designed to sell pickups and keep buyers from considering other vehicles. Which in turn are never "tested" and assigned "tow ratings" (a marketing term, not an engineering category), to the detriment of the general public.

There is no test for wind handling of travel trailers. In fact, there is no travel trailer testing at all. The "representative" trailer, isn't.

The trip down the garden path is the deception of "weight"'. It's only one of several considerations for what makes an excellent tow vehicle (most especially for a TT). By ignoring other factors, folks are left with the idea that this (series, actually) paper is relevant and leading. A high COG pickup with crude suspension is NOT an ideal. It's a ******* compromise.

N2807 may as well be a Unicorn Corral topic.

[mwilliamshs]

Originally Posted by Hersbird

The frontal aera limit is a bit general. I would figure the 60 sqft limit would be based on a towing a cargo container brick. Also that would be at interstate speeds. That 60 sqft limit is also on the f250 diesels. To be an accurate measure of the load on the drivetrain they would have to calculate a combination of speed, frontal aera and Cd.

Oh and what about headwind/tailwind? 60 sqft in a 40 mph headwind is different then 60 sqft with a tailwind. Dodge doesn't seem to list these restrictions on their 1500-3500 trucks. Seems like Ford just looking for an excuse to deny warranty claims.

My new 5000 pound camper has a frontal aera of 74 square feet not counting awnings and A/C unit so probably 76 Sqft. So a 1500 Ram is good to go but I guess I need a F-350 diesel in the Ford world.

Edit: I just saw the 60 sq ft Ford limit is f-150-f550 so I guess I need an f-650 if they even make it LOL!

Just as the weight limits aren't specific as to trailer brake type or rolling resistance of trailer tires, the wind resistance limits are a guideline for the customer and an exit-strategy for the manufacturer. I too would assume the 60sq ft limit is worst-case-scenario. Any thought given to the fact that an F250 has a larger front area itself than does an F150? Maybe each truck differs enough in that respect to have similar limits in their remaining available total?

Likewise, the larger truck blocks more of the trailer with its body so by default a larger truck can tow a larger trailer (with regard to frontal area) than can a smaller truck with the same frontal area limit.

[mwilliamshs]

Originally Posted by slowmover

SAE J2807 is expressly designed to sell pickups and keep buyers from considering other vehicles. Which in turn are never "tested" and assigned "tow ratings" (a marketing term, not an engineering category), to the detriment of the general public...

GAWR is an engineered specification but should be assessed in consideration of tires installed and their respective load ratings.
Front GAWR + Rear GAWR = GVWR (unless other conditions exist which reduce GVWR such as frame strength, suspension design, etc) Some pickups available with both leaf sprung and air suspensions share axles but rate the two methods of attaching the axle to the frame differently.
For single unit trucks (like pickups) GVWR = GCWR
GVWR - GVW = payload
GVWR - GVW = towing capacity

LOTS of vehicles other than pickup trucks have tow ratings, trailer weight ratings, etc. SUVS, minivans, crossovers, plain old sedans...not sure there's a category of vehicle which could be considered entirely void of that rating. Even my Harley has a trailer weight rating.

[Hersbird]

Originally Posted by mwilliamshs

Just as the weight limits aren't specific as to trailer brake type or rolling resistance of trailer tires, the wind resistance limits are a guideline for the customer and an exit-strategy for the manufacturer. I too would assume the 60sq ft limit is worst-case-scenario. Any thought given to the fact that an F250 has a larger front area itself than does an F150? Maybe each truck differs enough in that respect to have similar limits in their remaining available total?

Likewise, the larger truck blocks more of the trailer with its body so by default a larger truck can tow a larger trailer (with regard to frontal area) than can a smaller truck with the same frontal area limit.

The size of the truck doesn't factor into the frontal aera, unless the truck itself is bigger then the trailer in some dimensions. It's not the difference in frontal aera or the added frontal aera but the overall frontal aera. It's just a bad move by Ford you don't get with Dodge or GM, I have a feeling they would drop it if it were more widely known. Almost every modern travel trailer on the lot is more then 60 Sq ft frontal aera which means the only 100% acceptable tow vehicle produced by Ford is a f-550 with Max tow package. I agree there are other things to consider but I get blasted on any towing forum when I point those same arguments out as applied to the other numbers listed in the tow guides. Those numbers are also worst case scenario and will vary with other factors.

[mwilliamshs]

Originally Posted by Hersbird

The size of the truck doesn't factor into the frontal aera, unless the truck itself is bigger then the trailer in some dimensions. It's not the difference in frontal aera or the added frontal aera but the overall frontal aera. It's just a bad move by Ford you don't get with Dodge or GM, I have a feeling they would drop it if it were more widely known. Almost every modern travel trailer on the lot is more then 60 Sq ft frontal aera which means the only 100% acceptable tow vehicle produced by Ford is a f-550 with Max tow package. I agree there are other things to consider but I get blasted on any towing forum when I point those same arguments out as applied to the other numbers listed in the tow guides. Those numbers are also worst case scenario and will vary with other factors.

Yes, the size of the truck does matter. the 60 sq ft limitation is based on the total exposed frontal area, not the trailer overall. (I'll re-read the 2014 brochure linked to make sure I didn't overlook a big change) For years and years the Ranger limitation was trailer frontal area not to exceed that of the tow vehicle and F150 was tow vehicle +12 sq ft.

"Frontal Area is the total area in square feet that a moving vehicle and trailer exposes to air resistance..."

It's a combination of truck (Ford says the 2014 F150 is 36 sq ft) and trailer exposed frontal areas. So a bigger truck exposes less of an equally sized trailer, so a bigger truck can tow a bigger trailer.

[Hersbird]

Originally Posted by mwilliamshs

Yes, the size of the truck does matter. the 60 sq ft limitation is based on the total exposed frontal area, not the trailer overall. (I'll re-read the 2014 brochure linked to make sure I didn't overlook a big change) For years and years the Ranger limitation was trailer frontal area not to exceed that of the tow vehicle and F150 was tow vehicle +12 sq ft.

"Frontal Area is the total area in square feet that a moving vehicle and trailer exposes to air resistance..."

It's a combination of truck (Ford says the 2014 F150 is 36 sq ft) and trailer exposed frontal areas. So a bigger truck exposes less of an equally sized trailer, so a bigger truck can tow a bigger trailer.

How does a bigger truck reduce the overall exposure to the air? You don't get to deduct the size of the truck from frontal aera just because it hits first, it's still part of the overall frontal aera.
If you could deduct the 36 Sq foot of even a f-150 then you could tow a semi trailer and be under 60 (basically 96 Sq ft total. The difference between a f-150 and f-250s frontal aera isn't that much anyway.

Look again at your quote, it is the aera the truck AND trailer expose.

[aerohead]

Originally Posted by Hersbird

How does a bigger truck reduce the overall exposure to the air? You don't get to deduct the size of the truck from frontal aera just because it hits first, it's still part of the overall frontal aera.
If you could deduct the 36 Sq foot of even a f-150 then you could tow a semi trailer and be under 60 (basically 96 Sq ft total. The difference between a f-150 and f-250s frontal aera isn't that much anyway.

Look again at your quote, it is the aera the truck AND trailer expose.

As the tow vehicle frontal area approaches that of the trailer,the trailer is more and more in the draft of the TV.You can see some of this here

Here,NASA matches the two frontal areas for the same reason





Ideally,you'd match the frontal areas,seal the gap,and boat-tail the trailer