The first thing one notices about a U500 is just how far off the ground the driver seat is. There is an initial feeling of being up there but it is not obvious until one gets onto the road that this truck is actually taller than the tractor of an 18-wheeler. From the U500 drivers seat one can see the roof of an 18-wheeler cab.
The next thing one notices (at least if one is blessed with the non-automatic transmission) is the unusual gear change. There is this little nob between the seats with a complicated diagram next to it. Push it forward and the transmission is primed to shift up a gear, pull it back and the transmission is primed to change down. But what do I mean by primed to change. Well the actual change of gear does not take place until the clutch pedal is depressed and released. Pretty weird. To make it a little more complicated there is a lever on the front of that nob that also changes gears, pull the lever up is like pushing the nob forward, pushing it down is like pulling the nob back. The difference is the lever only changes one gear at a time where as the nob will actually skip gears and (the transmission computer will) select one (more )appropriate to your speed.
Once underway for the first drive the next thing to strike one is the combination of gear ratios and rev limits. This will be familiar to any experienced truck driver but to anyone not familiar with trucks (and I mean real trucks not pickups, not even F550s) this is going to seem like gear change hell.
The engine has a working range from 1000 rpm to 2000rpm. It can be pushed to 2700 rpm, but that is outside the green range on the tach, and at that point the governor cuts in, sounds a siren and prevents any further acceleration. And the gears are generally spaced so that 2000rpm in 3rd will get you 1400 rpm in 4th etc. Top speed is about 70 mph at the point where the governor screams.
If one selects 1st gear and changes up one gear at a time, 4th gear will arrive (or screaming from the governor) before the vehicle has crossed a typical intersection. Hence the more typical way to drive is to start in 2nd gear, then double-tap the gear selector to 4th, then double-tap again to 6th and there after change one gear at a time. This has the effect of making the 8-speed transmission effectively a 5-speed, at least for the purposes of driving on town/city surface streets.
Out on the highway our vehicle will run at 65mph on flatish terrain though it feels more comfortable at 55mph, which is more typically the speed at which I drive it. The torque from the straight 6 will carry it up many of the undulations one finds on the interstate highways in the plains states or midwest, but once into the mountains (say 395 in eastern California, the Trans-Canada through the rockies, or as we discovered Quebec highway 138 from Quebec City to Baie-Comeau ) you will be finding too much use for gears 5 and 6.
At any speed, but particularly at highway speed, this is a noisy truck. I am usually an XM Radio fan when traveling but in the Mog I find that listening to the radio requires too much volume. So I have learned to live without the XM Escape channel.
The cab can also be very hot, that huge windscreen gives great visibility but also collects a lot of sun. I am sure glad I opted to have a RedDOT after market A/C unit installed. On the way home from Overland Expo 2012 I drove through Death Valley, the temperature was 115°F but with the RedDOT inside it was adequately comfortable.
The Death Valley drive introduced me to another feature of the U500. To this day I am not sure of the exact combination of events but surfise it to say that climbing out of DV I got an over temperature warning from the computer. Being concerned not to destroy my new toy I stopped and let the temperature drop a bit and then proceeded to climb out of DV at 20 mph in 5th gear. I was forced to continued that practice on some steep hills on Hwy 395 the next day. Eventually I discovered (from experience and experts) that sometimes the engine computer forgets to turn on the fan. There are two solutions to this.
The first is to reset the computer (turn off the trucks battery disconnect for 30 secs). Thereafter (for a while) the computer will remember to run the fan when appropriate.
The second is to install a manual fan switch, so that the driver can turn the fan on in advance of steep climbs. I have subsequently had such a switch installed and discovered two related facts. Firstly I never use that switch, when the computer is correctly managing the fan the temperature rises but not to a point where an alarm occurs. Secondly when the computer is NOT managing the fan correctly the switch does not work correctly either.