*originally posted in Nov 2013*
Although the interior designs of Freightliners (or commonly known as Shakers or Fruitliners) haven’t changed much in the past decade, I like the Cascadia ergonomy still. Since that pic in the last update was taken a few years ago, I did move around some of the switches to my liking. That’s the only good thing about a multiplex system IMO. A multiplex is a ECU controlled system that works in pair with the engine PCM. That means it can recognize an electrical gauge or control switch no matter where you plug it and activates the proper signal or function. Nifty… when it works!
I do love how every component of the truck has a gauge, and I look at all of them often while driving. If you don’t, you’re not a good trucker IMO. Plus, it can help you guess the status of related stuff like oil level and brake temps; I can tell if my oil becomes low just by looking at my oil temp gauge, if it hovers slightly above coolant temp, it’s time to refill! Never been wrong so far. I can also tell if the brakes are overheating by looking at my diff temps. Drum types carry their heat well through the axles and to the diff. If it’s about to pass 200F, it’s time to take a break, lest you want to blow a tire or two!
I also closely monitor coolant temps in hills or mountain areas, especially if I have a heavy load. When it passes 210F I hit the fan switch which in turn helps draw air through the radiator but most importantly fully opens the thermostat for max flow. I’ve never overheated so far. Another important gauge is the suspension air pressure. You can easily convert PSI into approximate weight so that you’re legal at all times!
The only gauge that’s “missing” is EGT, but it’s there in warning lights form in the information center. I have a gauge that’s really old school mechanical: air restriction. With a diaphragm, it measures the force it takes to draw air through the air filter. That tells you when you need to clean or change your filter. It has a reset button for after you’re done!
The effective engine RPM range (max torque ~ max HP) of most class 8 truck engines is about 1200~1800. Mine’s a Detroit DD15 so it’s 1100~1750. It makes 1,850 lb-ft torque at 1100 RPMs. Depending on altitude and outside temps, that’s with about 28 to 36 psi of boost. That doesn’t sound like much, ‘eh ? Below 1000 RPMs you have no power, but from a standing start, you can still engage the lowest gear without any throttle application and the truck will begin going. Yup, even with a gross weight of 120,000 pounds (80K is the max on the US side). Them engines are straight sixes if you didn’t know, ranging from 13 to 16 liters of displacement. Smaller engines like 10 or 11 liters found in dump or box trucks often has a higher effective RPM range, but rarely past 2500.
I’m a old school stick man. Nothing beats a 13 on the highway! I know that newer autoshifts are praised for better fuel economy and driver retention, but I just like to have the ability to control how it goes myself. Mind you that stick shifting a semi (which has NO synchros) is starting to be a lost art with the newer generation of truckers. Heck, most of them have never even driven a manual car! Keeping constant track of road speed, engine RPM, and related gear is a foreign concept to them… I fear that the very tough upcoming laws on truck MPGs and emissions will kill the stick outright (it’ll be outlawed for the sake of ecology), and on that day I will either run my old stick truck until it falls apart or I’ll retire…