Power Up Hill

[garybo]

Considering the FG 140, I'd like to know at what speed the truck would "cruise" up a long 6% grade holding the tach at about 2200-2400rpm with different loads in 1000 lb increments from 1000 lb to 8000 lb. Cruise means a steady speed at the set rpms. I'm trying to estimate what load would cause the truck to get below 40mph and make every one backing up behind the truck very animated, ie, what weight camper would be maximum to get up hill at greater than 40mph.
In some countries, speed up a hill wouldn't matter, but in the US it does. This is a general question, not meant to get too scientific about tires, wind speed, road conditions, etc. If someone has a known weight camper, their input would be valuable. thanks

 

[SkiFreak]

Westyss has a FG140 that is fitted with a Steinbauer power chip. His setup has a switch that can enable/disable the chip, so he could probably give you an idea of what a "standard" FG140 is like up hills compared to when you chip it.
I know that he has noticed a significant difference going up hills after fitting the chip. You can read about his experiences in his build thread, should you be interested.

 

[kerry]

It partly depends on elevation. On my 99FG there's a wide gap between 3rd gear and 4th gear. I'm running around 12k lbs. Lots of hills in Colorado and the west I can climb in 4th gear which means in the 40's mph. But the steep ones put me in third and given the big difference in gear ratios, it drops the speed unless you really want to wind out the engine. I don't find the FG's climbing ability under load to be a problem at all. It does far better than my 1977 Mercedes 300d naturally aspirated. However, if you're used to driving a US high powered diesel pick up truck, you might feel differently.

 

[mog]

This is the only ‘flaw’ that I can find in my 2002 Fuso FG (stock drivetrain at 12,500 lbs w/ 37” super singles)
It is slow on grades. At 6% grades I’m down at 35-40 mph. As Kerry mentioned there is a huge jump from 4th to 3rd gear, so 35 mph in 3rd gear seems much worse then 35 in 4th gear.
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Now for real world experience. What seems like forever when you are on the hill, if you track the data it is really not a huge difference in drive time. A trip of 240 miles I make regularly that has 6 hills in the 5-6% range and I spend less then 15 minutes or so pulling those hills. But if I factor in that I was only going to be going 55 mph anyway (my normal cruise speed), what seems to be forever on the hills adds less then an extra 3 minutes total to a trip that is 4.5 hours long. So from a getting there stand point, the slow speed is not relevant (except seat-of-the-pants).
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From the ‘other’ traffic standpoint, for me it is not a factor. If there are passing pullouts and traffic behind me (even one car), I move over and let them pass. At least in my area, people understand you are slow (lots of motorhomes either slow by power or slow by driver), so if you get over when you can, they are very happen. I’m the same way when driving my car, hey if you move over when you can, thanks and a happy wave, if you pass a bunch of those pullouts and are still dragging, *$#%$.
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On the 6% hills, there are ‘other’ motorhomes and semi-trucks that are slow also, generally in that 35-40 mph range, so it is just one line of slow pokes which I am part of, so again, not a issue.
Down the road I’m thinking of adding water/methanol injection, not so much to go ‘faster’, but to be able to at least stay in 4th gear at 35-40mph on hills, and not have to make that dreaded 3rd gear downshift. But time will tell.