My 1999 F53 has a 275hp, non-pi, 2 valve V10, and a 4R100 3 speed transmission with overdrive. (4 speed) . The subject comes up often about how this motorhome performs in the hills and mountains. When looking at driving technique, also consider the effects of altitude. At sea level, this engine is capable of 270hp, but drive up to the Eisenhower Tunnel on I-70, (11,000 ft) and the max this engine will put out is a meager 175 hp.
Over the years, I’ve developed a technique that gets me safely up and down the hills mountains without rattling my nerves and I believe is a lot easier on the motorhome engine and transmission.
First – Remember rpm is power.. I need power to climb a hill. The V10 will run all day long at 4,000 rpm. This rattles a lot of nerves, but I got used to it.
Second – Monitor engine temperature, The radiator fan clutch doesn’t seem like it wants to kick in if the rpms are over 4,000 rpm. To get the fan to kick in, lower the speed and corresponding rpms.
This is generally the technique I’ve developed for dealing with hills and mountains.
I do most of my flat land and mild hills with the cruise control (CC) on. One thing I noted, if the CC holds the pedal on the floor to long, it will disengage. This will get your attention REAL FAST. I’ve learned to know when this might happen so I usually hold the pedal to the floor and tap the brake to disconnect the CC.
Mild hills
If I’m in mild hills, I still use the CC, but help it a little by turning the OD off just before starting up a hill, or wait until it downshifts out of OD to 3rd, then I’ll turn the OD off. This will give me a little more rpm (which is more power) to climb the hill. When I get to the top, I turn the OD back on.
Steeper hills (mountains)
On steeper inclines, I generally turn the CC off and manually shift. If its a long steep climb, I select a gear and speed that gives me a constant 4,000 rpm and allows me to make the climb without having the pedal on the floor.
I’m doing these from memory, but these are my speeds and gears when climbing
25 mph 1st gear = 4,000 rpm
45 mph 2nd gear = 4,000 rpm
65 mph 3rd gear = 4,000 rpm
65 mph OD = 2,500 rpm.
Most of the minor hills are done with OD off. Most of the steeper climbs are done in 2nd gear, and on rare occasion, I’ve had to make a climb in 1st gear.
IMPORTANT – Going down hill is similar. The goal is to not let the Motor home pick up speed to quickly. Lower the speed and if necessary, manually downshift. DO NOT ride the brakes. i.e. if I have a target speed of 45 mph, I’ll allow it to build up to a little over 50, then do a medium to hard application to drop back down below 45 then get off the brakes. If it builds up speed again to quickly (say 10 – 20 seconds) I’ll either downshift or lower my target speed down to 40.
If you experience fading, IMMEDIATELY slow WAY DOWN, get into a lower gear, and then get off the brakes to allow them to cool.