What would you consider adequate climbing performance? We have a local hill that might make a good test hill I think.

It is legal for Class 8's but there is a cautionary sign advising loaded trucks to take the alternate route that adds about 7 miles. The trucks I've gotten behind on it that appear to be heavily loaded pull it between 12-17 mph and dropped driveshafts are a regular occurrence. It's marked a 13% Grade.


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depends how heavy the load is your pulling. but even without any trailer, any vehicle is going to be pulling its own weight hard up a 13% grade. that is super steep. i wouldn´t be concerned about dropping the driveshaft in an f150, biggest concern would be overheating the transmission in a situation like that

 

There are two major things I ever worry about in steep hills. Transmission temps going up and brakes on the way down overheating.

 

Adequate climbing performance is getting to the top of whatever you're trying to climb.

If you're towing an outboard boat from New Orleans to Winnipeg, "adequate" is much lower than towing a loaded 5er from San Antonio to Phoenix. Where are you going, and what are you trying to pull there?

 

TFLs Ike gauntlet?

 

ha! im with you on that. i had a load on my 2004 once and 10 mph was all it could do WOT up a hill on a country road. it was about 16,000 pounds, 21,500 pounds gross. i was worried i wasn´t going to make it up, but the ole 4.6 made it happen. i pulled everything under the sun with that truck and hell its still running, my cousin uses it to haul horses. last time i checked in on it it had 275k miles

 

We were doing a dirt bike trip up at Sierra Buttes, CA in an old ford powered RV and a dirtbike trailer. We had to get out and push it to camp. The owner sold it after that trip! I think we were at 8 or 9 thousand feet.

 

Ike is used as a testbed because it is high altitude. Highways are maxed at 6%, except when the speed limit is below 60, where 7% is permitted. The makeup of the Ike Gauntlet is the max grade for a highway at high altitude.

I drove the auto road a few years ago, it averages 12% with a peak of 18%. 7% is steep, but 12% is a different beast. Loaded to about 6500lb with no trailer, using brake smell to initiate pull offs, I had to cool down three times during the 7.6mi run. That's a cool off every 2 miles. There is no such thing as effective engine braking at grades like that, even in first gear the tach marches off toward red, V6, V8, 3.5, 6.2, doesn't matter.

 

Auto road?
This https://mt-washington.com

 

Yep, that's the one. We went because I wanted to visit where the fastest winds were recorded in the US (231mph, world record until 1996, still the world record for surface winds) during a trip to Maine. We left the base of the mountain at 84ºF, at noon-ish. Was 65º at the summit. About an hour after arriving at the summit it went from sunny to overcast and temps started dropping. By the time we got back down, it was had dropped from 84 to 60 and was expected to drop another 10ºF. This was July, at a 6288ft mountain that's just 4618ft above local terrain. You get a little bit of cloud cover to squelch the heat coming off the land, that mountain drags cold mid level winds right down it's slopes.

There are a ton of restrictions on what you can drive up the mountain. Ex. no more than 900lb of people and cargo in any vehicle under 1 ton. If your vehicle can't lock into first, you can't take it up. No trailers or RV's of any type, including any type of van conversion.

The road is closed at night due to the dangers of driving it. They have days where you can drive up early enough to see the sunrise, but may cancel due to weather, as even during the middle of summer there can be overnight ice formation on the road.