RPMs dropping uphill, Ford f-450
We are experiencing odd vehicle problems and were wondering if anyone has any ideas. When going uphill (~5% grade @2500 ft above sea level), the rpms slowly decline, pedals wide open throttle. Dual co...
Forum Discussion
blt2ski wrote:
Assuming you are around 25,000 lbs total. 100+sq ft of frontal area. You need 150-175 hp to go 60 on a level ground. Another 50-55 hp per 1% grade. You are needing more HP than you have. Yes you should be slowing down some.
Also, I don't believe a 2013 has 400hp. But could be wrong.
Marty
Yep, like Marty says you're bumping up against the laws of physics. The 2013 is rated at 400 hp but it's not putting that much to the ground. People like to crow about how their rig can "pull 30K up a 6% grade at 80 mph" or some such nonsense, but typically they are fibbing about the weight, the grade, or the speed, or all three. To give a basis for comparison, a semi I sometimes drive weighs 30K empty and pushes a similar frontal area to your combo. Hammer down, it will pull a 6% at 60 with a good run at it, and it has 10 speeds, 515 chassis dyno certified horsepower and over 1500 ft.lbs of torque. Loaded to 72K it's more like 40, and that's not bad. So if you're getting pulled down to 50 or so on a 5% grade weighing 25000 lbs combined, it's not the truck, it's just math.
