Today I find myself replacing drive tires. These tires are prematurely being replaced as they still have a 6/32 of tread on them. The tires I am replacing are Michelin X1 Line Energy D 445/50-22.5 wide-base tires. These tires started life with 24/32. They are designed to do two things. First is to save weight, and the other is low rolling resistance to save fuel.
I decided to replace them early as I had some time off in my schedule, and there is still some possibility of some snow. The wear rate of these tires came in at 18,855 miles per 1/32. If this had been summertime, I would have run these tires much closer to the minimum tread depth of 2/32. This tire wear means I could have easily got another 60,000 miles before replacing them.
What really impressed me is the fact that these tires have a large number of miles at 75 mph due to my project 70+/10. The goal of this project has been to achieve double digit fuel economy while cruising at speeds up to 75 mph wear safe, posted legal, and prudent.
While the tires were being replaced, my mind went down a rabbit hole of thoughts of how much the trucks have changed in the span of my career in this industry since 1983. I still remember when it was the standard practice to install new rod and main crankshaft bearings every 250,000 miles. It really struck me that in today’s world, we expect more than a million miles from our diesel engines before they require any major internal repairs.
I started to think of how much more comfortable the trucks are today than when I started. Back in the so-called “good ole days,” you could not even dream of standing up in your sleeper or cab area to get dressed. In the old cabover designed trucks, you had to climb over the dog house, enclosing the engine, slide your way back into the sleeper, and start a process of shimming into or out of your clothes while getting into bed. There were no cabinets to hang your clothes, refrigerators to store your food; in fact, the only thing in your sleeper was a dome light, a cheap mattress, and possibly a vent that could be opened either side of the sleeper berth for ventilation.
Engine brakes were a rare luxury for descending hills without overheating your drum brakes. While we are on brakes, it’s funny that today there are disc brakes on many of the trucks and trailers, which makes me think had they been the norm when my career started that the engine brake would never have come into existence. Brake fade from heat is no longer a worry like it was back in the day due to improvements in disc brakes.
Let’s talk about the ride for a little bit, as there are many drivers today that have never driven a spring ride truck. Back in the “good ole days,” the only thing that cushioned you from the bumps in the road was an air ride seat. I still remember how much you would move up and down in the seat on a rough road while trying to keep your foot smoothly on the throttle or brake. On some roads you felt as if you were on an amusement ride as you got pitched up and down in your seat. Keep in mind, this is if you were fortunate enough to have an air ride seat as there were many trucks where the seat had no suspension, or one truck that I drove, which had a spring ride seat. Oh, how I still remember this wonderful marvel of a 1984 Brigadier GMC, which had one of those wonderful spring ride seats. Keep in mind, this was one of the last “real” trucks; all-steel cab, steel dash, steel doors, no insulation, and no air conditioning. So here I am 6’5” tall in this small cab where my head is nearly against the all-steel roof, with a spring ride suspension under the truck along with a spring ride seat which would occasionally launch you into the ceiling which would make you see stars. Most of these older “real” trucks did not have enough cab space or adjustability to accommodate taller drivers so, you would scrunch down on the seat with your knees up, towards the dash, which did wonders for your back, so that your head did not hit the roof.
Oh yes, the good ole days and the three herniated discs I have in my back from the “real trucks.”
As I look at my sleek Freightliner Cascadia Aero X powered by a Detroit DD15 and DT12 automated manual transmission sitting on air ride suspension, air ride cab, and a comfortable air ride seat, I have no desire to go back to the so called “good ole days”.
I hope you enjoyed going down the rabbit hole with me as I journeyed back through my career as my new tires were being installed.