Technical Oil change frequency

I have what I would consider excellent winter storage conditions, so I think I'm on the right path here.

 

Once a year for me with oil that’s made for my vintage engine. Mostly in town driving and never more than 1200 miles in any year. Same with my wife’s 2015 Honda Civic 19K miles in 10 years. Once a year with a catch can added.

 

I do mine once a year because I know it'll get done. If I were to skip a year because of not enough mileage, I would get all out of sync and perhaps miss multiple years.

 

Just wondering........how often do professional over the road semis change their oil? Yes, I know they are diesels, but diesels are "dirtier" than even older gasoline engines which operate dirtier than the newer automotive gasoline engines...............so whats a general rule of thumb for changing oil in them?

 

I used to run Freightliners and Internationals. Seem to recall 20k.
My memory has taken some hits the last ten years.
So I checked, and found Cummins looking for 30 thou.
There were during my time on, the hi-ways, increases due to better oils and better filters.
To give a perspective I would aim for driving 3,000 miles a week.
BT W remember that gasoline is a solvent. Diesel fuel is oil.
Another thought about the span is that many trucks aren't shutdown. No
break, or heat cycle.
The mention of Diesel being dirty refers to the combustion particulate emissions not the crankcase.
Since I'm already off the track, ( thank you @ekimneirbo ), I'll toss out this factoid.
Diesel discovered the property of combusting oil through molecular friction with a pipe about 6? feet tall.
He'd put some oil in and shove an airtight plug into it.
The result of squeezing the oil hard enough, resulted in an explosion.
He then named it "The Oil Smasher".
Later came the pistons, crankshaft, rods etc.

 

Lets not forget that diesel motors generally have a lot more quarts of oil in them then car motors do. Ten quarts of oil can handle 2x the amount of contaminates and moisture that 5 quarts can.

I have seen the issues that long term 5,000 mile oil change intervals, without any time concerns, have caused inside of motors, and its not pretty. The motors may still run, but there is a lot more wear in motors that do not get timely oil changes.

If you are not putting a lot of miles per year on your vehicle, at least change the oil and filters at the same time, every year. Get the motor thoroughly warmed up, and drain the oil while its still warm, so it pulls the accumulated contaminates out of the motor mixed with the oil you are draining. Then change the oil filter before you add the fresh oil.

 

My flathead (like it's owner) doesn't have a filter so I change it every winter.
My Olds has a 10 quart pan (left over from racing days) and I can only afford to change it every other year. The rear main leak assures it gets a fresh quart now and then.
The hemi in the PU hasn't been driven enough to worry about it (tranny issue they aint identified yet).

 

More oil in say a big cam Cummins, 11? Gallons as I recall, which adds to your reply.
Maybe 11qts is vehicle diesel?

 

The 10 quarts compared to 5 quarts was to show how much difference more oil can make in any contaminate or moisture situation.
I don't play with diesel stuff much, but I believe most modern diesel pickups have at lease an extra couple of quarts of oil.

 

A prior owner of my wagon left me this mess from not changing oil frequently enough.
The only problem with changing oil too often is cost.

 

The typical 11 L or 12 L heavy duty diesel engine has between 38 and 40 quart oil capacity with filters.