Towing Weight vs Frontal Area Ratings

[gnies]

[quote timestamp="1468784839" author="@exploringcarolina" source="/post/23126/thread"]David,

Appreciate the information. 

Looks like the F-150 3.5L EB produces more HP/Torque at lower RPMs compared to the F-150 5.0L engine.

Honestly don't know yet, how the 3.5L EB stacks up against the 5.0L durability under the same conditions. The 5.0L and 3.5L EB F-150 are both on
my radar at this time. We were also surprised by the 261HP normally aspirated 4.0L Frontier Performance with our "new to us" TT.
It's fun to research, will see!

Here's some 2016 Ford gas power plant numbers not including the more powerful/higher torque 2017 3.5L EB.

2.7L EB    325HP  @ 5750RPM 375 lb ft @ 3000RPM

3.5L EB   365HP @ 5000RPM  420 lb ft @ 2500RPM

5.0L Coyote 360HP @ 5500RPM 380 lb ft @ 4250 RPM    

Ford information source:   http://www.f150hub.com/tech.html[/quote]I have the 2.7L EB engine and I can tell you that I am very impressed by is towing capabilities vs my Escape! My particular combo (engine/options) can tow 7500 lbs and has a payload of 1440lbs. The economy of gas while not towing is really impressive! While towing not so good but better than while towing with my Escape. On the highway I was able to get 25 MPG and towing about 13-14 MPG. Also with the 36 Gallon gas tank I don't have to stop often for gas. I was able to do a 7 hour drive with my trailer and when I was home I still had some gas left, with my Escape I would have stop at least twice during the trip.

[spot1]

[quote source="/post/23158/thread" timestamp="1468847020" author="@paul"][quote source="/post/23126/thread" timestamp="1468784839" author="@exploringcarolina"][/quote]I have the 2.7L EB engine and I can tell you that I am very impressed by is towing capabilities vs my Escape! My particular combo (engine/options) can tow 7500 lbs and has a payload of 1440lbs. The economy of gas while not towing is really impressive! While towing not so good but better than while towing with my Escape. On the highway I was able to get 25 MPG and towing about 13-14 MPG. Also with the 36 Gallon gas tank I don't have to stop often for gas. I was able to do a 7 hour drive with my trailer and when I was home I still had some gas left, with my Escape I would have stop at least twice during the trip.
[/quote]Paul,

Appreciate the Ford 2.7 EB information.

25MPG is fine economy for a F-150 Pickup while not towing. 13 to 14  MPG is not bad while towing and the large fuel tank is nice to have, too! We have two pickup trucks. Our other PU is a Tacoma. Looking seriously at the 2017 F-150 for the next TV!

Thanks,

[david]

[p]This post is a take off on another thread about towing a CL21 with a medium size SUV like the Highlander and is for the technonerds. It is both somewhat theoretical and somewhat empirical. It is based on a 5,000 lb TV like a medium SUV towing a 4,500 lb trailer like a CL21.[/p][p]
[/p][p]At a flat land steady state of 60 mph, such a rig should get about 12 mpg. Since a gasoline engine typically makes 12 hp for every 1 gph of gasoline it burns, that TV is producing 60 horsepower. 60 hp is ok for a 4 liter engine at 15 hp per liter, but a bit high for a 3 liter engine at 20 hp per liter. The more hp per liter you require long term, the shorter the engine life will be.[/p][p]
[/p][p]So now lets go up a hill. The first example will be a 4% grade, sort of a medium slope. It takes 60 hp to pull the rig up that slope in addition to the flat land hp. So it takes a total of 120 hp. That will drop your instantaneous mileage to about 6 mpg.[/p][p]
[/p][p]Now lets try an 8 pct grade, about the steepest I have seen in the eastern US. If you try to maintain 60 mph up that grade it will take a total of 180 hp to do that and your instantaneous mileage will drop to 4 mpg.[/p][p]
[/p][p]If you had a manual transmission and kept it in high (5th or 6th) gear, you couldn't do it. Assuming you were doing 2,000 rpm on flat land, most 4 liter engines can't produce 180 horsepower at 2,000. If you downshifted a few gears and were at 3,000 rpm you might be able to do it but your engine would probably be maxed out because the hp curve is probably near 180 hp at 3,000 rpm. You really would need to down shift more and let the engine rev to 4,000 to have any hope of doing this for more than a minute.[/p][p]
[/p][p]There is one grade in southern Vermont that we go up that ranges from 6-8% for five miles or so. If I ran that at 60 mph and 3,000 rpm I guarantee that my engine would be overheating after a few minutes. And if I did that routinely my engine wouldn't last very long.[/p][p]
[/p][p]So slow down and downshift on long, steep grades- duh, right!! If you take the 8% grade at 40 mph and 3,500 rpm which is what I do, the engine has to produce only 100-120 hp due to spreading the climb over more minutes and the square root effect on wind load by slowing down. While 100-120 hp is a lot, a 4 liter engine can probably produce 200 or more hp at that rpm so the cooling system won't be badly taxed at that rate.[/p][p]
[/p][p]I see a lot of posts on this forum about going up hills and mountains with no slowing down. It seems to be the holy grail of having enough engine. That is fine if you have a 5 liter V8 or bigger. But if you have less, slow down and downshift to let the engine rev up to where it is up high on its hp curve. The engine will like you for doing it.[/p][p]
[/p][p]David[/p]