20,000 hrs and 310,000 miles?

Order a analysis kit, you just put a couple ounces of oil in the bottle and ship it to them. Likely your local truck repair would have the kits on hand, maybe even offer you a deal to send your sample in bulk with theirs. Might as well test the coolant also.

 

That mileage on those hours font match unless there was a ridiculous amount of idling

 

As far as hours vs mileage, I'd not worry too much about it. Lots of idle time + lots of slow miles in aggregate.

 

Our mixers always had tons of hours on them. Just the nature of the beast, as the drum has to keep turning. Probably the same with your Mack, lots of stand by time, getting loaded, and staging, plus you want that A/C in the summer time.
I drove this Pete that's pictured in this avatar, and it was one of the oldest trucks in the fleet. It used a gallon of oil maybe every 6 weeks, pulling 75K all the time, 900 or so miles in town a week, engine running basically 55 hours a week on average. Cummins ISM engine. Ran great, all kinds low end pull. It has about 20,000 hours on it. The Cat's didn't do as well.

This was an '05 as well, So yours doesn't seem to out of whack for '00.

 

We had a 2001 Century, put 220,000 on it in 10 months team work with approx 301 days farther than 100 miles from home according to our taxes for that year. Call it 7000 hours on the engine with two burnt alternators, one failed transmission software issue (Auto, believe it or not, it did well) and a set of bobtail tires for winter.

Switch to hauling rock or a cement mixer. You idle and idle and idle. There were days we put in 20 hours over time waiting on callbacks 7 miles away. In those days there were no idle laws worth a #### and I usually keep that sleeper truck or day cab nice and warm or cool depending on season, fuel and idle be ######.

Today, I think anything up to a 300,000 mile over the road rig within 2 or 3 years is a good one depending on it's maintaince breakdowns if any. Those will tell you the story. If you are getting up into the 500,000 to a million miles, you are going to have something somewhere not quite tight. The more it goes the looser they get.

I had one approaching 40 years held together by rivets in a local little rock company once. Until the entire floor and seats fell down to ride on the frame rails at 80 mph on I30 one fine day with me inside wondering if that drive shaft will hurt as it wraps me.

Im willing to try anything once. But Im wise now. I check the records of everything offered to me to drive. If I cannot satisfy myself with the "Story" of that history then I wont take it.

 

First company I ever worked for had a pair of '03 Western Stars with 21k hours and only 50k kilometers. Trucks did a lot of stationary work running the PTOs mainly. 20k hours on an engine is getting up there though.

 

I agree, 20K is getting up there.

I was thinking about this topic tonight and recalled a old Mack 500 SuperLiner converted 5th wheel to blacktop dump truck I had for a couple years in that work. That thing had almost a million in total, 15 speed double under foward and back, still lugged to 950 rpm if necessary. Not everything was tight... eh... but it did well passing DOT tests and inspections now and then.

Ive driven many trucks, but only a few are my favorite in memory and that Superliner 500 was one of them.

 

get an ECM dump, & see what Hours/miles It says.
It may have had a new speedometer....