[Fluff time] On a long road trip what would be the worse occurrence to manifest on the trip details inside?

Jerez, I’m a truck driver and have been hundreds of miles from home when crap happens have had the accessory drive shaft snap dead in the road waited three hours for a wrecker,have had countless tire blow outs, have had the drivers side window shatter showering me with glass,at the same time the headlights shorted out three hundred miles from home,want me to go on??
Oh how about this, a bad snow storm you can’t see twenty feet in front of the truck and you still have five hours before you get home.

A rod knock is pretty bad whether it’s a wrist pin or rod journal bearing. I would say no oil pressure would be the worst. Everything else I could deal with.

Oil pressure dropping to nothing with a hundred miles to go is the most threatening, but you could pull into the nearest gas station and buy a couple quarts of oil to hopefully get you home unless the lead is catastrophic.

Over heating in stop and go….2 choices….turn the heat all the way up on full blast will usually pull enough heat off the engine to help cool it down…again find the nearest gas station and let er cool down and check coolant levels.

A medium rod knock again would push me to check oil levels at nearest gas station but not a panic moment…just know there is a sizeable service bill in your future unless you have kids like I do who are expert mechanics and fix it because they love thier dad.

A rock pebble creeper no worries…I make epoxies that will fix that. If it is dangerously cracked a replacement windshield when I get home is in order no choice in the matter.

Gauges and radio crap out is no biggie as I drive with my MP3 player on my cell phone and don’t really need a gauge to tell me how much gas I have put in my tank or how fast I am going as my Waze app on my cell tells me how fast I am going and where all the cops are hiding.

No oil pressure is the only defect that guarantees destruction of the engine and quickly.

Sorry to really answer your question low oil pressure would be most concerning but the computer in the big truck would shut the engine down before any real damage would result.
Oh and it does give you a thirty second notice so you can get it off the road.