De-rate F150 Towing Capacity for elevation

[aircommuter]

Originally Posted by TitanMike

If one is worried about "towing" and "mileage" they are in the wrong "sport".

For sure, like my houseboat 6mph, mpg as needed.
Tanks hold 312 gallons.

[pgandw]

Originally Posted by moose074

I know I posted earlier in reference to SAE J 208. Allow me to go a different direction

Average hp by decade gas engine
2020 376 ( GM 5.3, Ford 3.5 Ram 5.7 Tundra 5.7 )20% decrease 300hp

2000 263 ( GM 5.3 Ford 5.4 Ram 5.9 ) 20 decrease 211

1984 167 ( GM 5.7, Ford 5.8 Dodge 5.9) 20 decrease 134

So as you know many people pulled trls long before the 80’s they crossed over mountain passes up and down. I understand my method might not make sense to some but again. We worry about little things

But they didn't pull those trailers at 75mph over the mountain grades. Cooling is everything; there used to be a lot more cars and trucks pulled over on the side of the road blowing steam from their radiators than nowadays.

The amount of heat needing to be gotten rid of into the thin mountain air (air cooling is a lot less efficient at altitude) is double what it used to be on the older trucks. Truck and car engineers have gotten much better at providing adequate cooling.

The engine torque/power decrease with altitude is real, and so is the reduction in aerodynamic drag. But when you are dragging an 8,000lb trailer up a 6% grade at highway speeds, cooling is going to determine how long that engine and power train is going to last.

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Kia Carnival minivan
camping whenever and wherever we want in one week

[moose074]

Originally Posted by pgandw

But they didn't pull those trailers at 75mph over the mountain grades. Cooling is everything; there used to be a lot more cars and trucks pulled over on the side of the road blowing steam from their radiators than nowadays.

The amount of heat needing to be gotten rid of into the thin mountain air (air cooling is a lot less efficient at altitude) is double what it used to be on the older trucks. Truck and car engineers have gotten much better at providing adequate cooling.

The engine torque/power decrease with altitude is real, and so is the reduction in aerodynamic drag. But when you are dragging an 8,000lb trailer up a 6% grade at highway speeds, cooling is going to determine how long that engine and power train is going to last.

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Kia Carnival minivan
camping whenever and wherever we want in one week

I wouldn’t argue with that statement one bit. I would say more made it then didn’t. Can’t tell if you got my point though , which is that even with the drop in power we are still almost double the horsepower from 37 years ago, when you attach something to the back of a vehicle, add weight to it , pull a huge parachute or go up hill you are working the engine harder. Yes vehicles are made better than ever part of my point, but so is the oil , gas antifreeze ect. My point is the majority are still going to make it. I don’t have to be to the top first. I just have to make it there.

[TitanMike]

Originally Posted by aircommuter

For sure, like my houseboat 6mph, mpg as needed.

Tanks hold 312 gallons.

My old 35' Cruiser was a little faster but fuel consumption was around 10 gallons per hour. Two inboard 225hp engines.

My truck is an economy car when compared to the boat.

[Bhrava]

I think the derating is mainly for the NA engines since turbos overcome the thinner air. The frontal area is really that which extends past the cab as it is the only part in the airstream. The tailgate designs create an air cushion at highway speeds which creates a bubble for air to flow over, so works for conventional as well as 5th wheel. Bugs on the cap is a great indication to what part to measure, then factor in the CoD of that section to get the true frontal area.

Of course one needs to know HOW to calculate that, but have yet found a mathematician who does.

[aircommuter]

Turbocharged engines will also have less total boost and lag more until boost is achieved.

[cknsls]

Originally Posted by pgandw

But they didn't pull those trailers at 75mph over the mountain grades. Cooling is everything; there used to be a lot more cars and trucks pulled over on the side of the road blowing steam from their radiators than nowadays.

The amount of heat needing to be gotten rid of into the thin mountain air (air cooling is a lot less efficient at altitude) is double what it used to be on the older trucks. Truck and car engineers have gotten much better at providing adequate cooling.

The engine torque/power decrease with altitude is real, and so is the reduction in aerodynamic drag. But when you are dragging an 8,000lb trailer up a 6% grade at highway speeds, cooling is going to determine how long that engine and power train is going to last.

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Kia Carnival minivan
camping whenever and wherever we want in one week

For those of us who live in the Mountain States and tow up 9,000 foot passes at 90 degrees-TFL's situation is REAL WORLD. I was told by a 3.5 Eco-Boost owner that my Silverado 5.3 is actually 250 horsepower (factory 315 -I believe) going up these passes. While I don't know if that is accurate or not-one thing I do know is that it will pull my 5,000 pound travel trailer up 9,000 foot passes at 90plus degrees and not over-heat, since I have done exactly that dozens of times.

[lewisra]

Originally Posted by cknsls

9,000 foot passes at 90 degrees

That's some steep ass mountain roads!!!




YIKHTT

[nomad297]

Originally Posted by lewisra

That's some steep ass mountain roads!!!




YIKHTT

Yes. I always use my train of mountain goats that I keep in the bed of my F-150 when I am faced with this situation.

Bruce

[Rick J]

Originally Posted by Boomerweps

Saw it referenced in an overheating TLLTruck Utube.
Confirmed in last three years F150 Owners Manuals.
Ford says to de-rate your F150 Towing Capacity by 2% per 1000 feet elevation above sea level.
It’s in the Towing section after the pro trailer backup instructions that kinda breaks the towing info in half. 2019 page 297, 2020 page 302, 2021 page 375.
I.e., towing through Denver, you lost 20% or more of your capacity. Another reas


on to avoid pushing towing limits.

That truck only overheated because those TFL loons do not drive like normal people. They had the truck at the max and run at wide open throttle instead if downshifting manually and keeping a decent speed in the engine's torque range.

[Rick J]

Those idiots on TFL put the pedal to the floor and see how fast they can go. Nobody drives like that. If they would have manually put the truck in a gear where the engine was in it's torque range it would have easily ran up that hill all day long. An EcoBoost gets maximum torque from 2700 to 3700 rpms. Those fools were running 4500 plus, which reduces the torqu.

[Rick J]

The frontal area if the traIler incldes the truck because the truck blocks part of the trailer. You don't add the truck area.