Do you really have to change the oil in your Bus Engine?

[Gary Hatt - Publisher BCM]

I once heard that Greyhound Bus Lines never changed their engine oil; they only changed their Oil Filters and added oil PRN.  The theory is that oil never breaks down. However, I don't remember who told me that, and I am not sure it is actually true. Can anyone verify whether this is a true statement for Greyhound in the past or in the present?

Rather than taking a chance to cause a premature and expensive engine rebuilding job, I generally change my oil at around 7,000-mile intervals or whenever I am at a place where it is convenient.  Last year, it took me 12 months to travel that far. I also draw off an Oil Sample and take it down to the CAT House or a similar testing facility to have it tested for contaminants.

BTW, I was in a Diesel Chassis Maintenance seminar at FMCA in Tucson last month, and they said to change your oil at least once per year, no matter how far you drive. 

I do not use synthetic oil in my Series 60, I use conventional oil which better aligns with my Pay Grade. 

What are your thoughts on this?  Do you change your Oil Filters regularly and simply add oil as necessary, or are you a believer in changing your oil at regular intervals?  If so, how often do you change your oil, and do you do it yourself?

Also, do you use conventional oil or the more expensive, highfalutin synthetic oil?

[muldoonman]

Not changing oil is like not changing your undies. Both bad.

[luvrbus]

I have some old service records from Greyhound in Dallas ,back in the 60's and 70's they had a strick maintenance program oil was changed every 7500 miles lol and they use Gulf engine oil engines were changed at 250,000 to 275,000 miles.I have seen crankshafts turned so many times Greyhound had special bearings made you could not buy from Detroit

[CrabbyMilton]

That may have been a second or third hand urban legend. Engines love fresh clean oil. If they don't get fresh clean oil on a regular basis, they won't like you and do nasty things like turn into oatmeal on the interstate.

[Gary Hatt - Publisher BCM]

Do you mean like this engine?   

https://munichmotorsport.com/services/15000-mile-oil-change/

[CrabbyMilton]

Holy Crap!!! That's almost scary looking much like a insect B movie.

[luvrbus]

All the additives in oil now you have to change,my dad and granddad never changed oil just a filter and add a quart in their pickups,it never carried over to me though ,I never saw a factory oil filter on cars and pickups till 1956 it was on a V8 you always had to pay extra for dealer to install the oil filter

[sledhead]

I run 100 % syn oil that I buy on sale and every year I take a sample to the cat guys and get a report back on email. every time they tell me all is good and no nead to change . I would change the filter and top it up and change it the next year. But still got a report back saying all was good and no need to change it .

so I only changed the oil every 2 years but my milage after I changed it was low at about 10-12 k miles in 2 years

as I did not drive the coach much in 2020 and 2021 due to covid crap and the border was closed for the 2020-2021 winter . I still sent in the sample and change the filrter and top up the oil every year . so it was 3 years now and I sent in a sample last december ( 12 k on oil ) and again no need to change oil again from cat  so I put anouther 5 k miles on it now total of 17 k miles on the oil .
but the oil last december was still a goldish colour
my cat 3406 e takes 42 litres of oil on a change so this might have something to do with the no need to change the oil reports
but I am going to change the oil before I go south this year  and send in the sample of the old oil and see what they say
sounds scary but because I do not put that many miles on it and save $ on the syn oil and the fact the pig takes so much oil on a change I think everything is fine

[Iceni John]

Or we could do what the railroads do (did?):  https://cs.trains.com/trn/f/741/t/173471.aspx

John

[Coach_and_Crown_Guy]

I suspect the legend of Greyhound not changing the oil may have been born out of the well known fact that the Detroit 2-strokes used exclusively in their fleet and universally in most all buses at the time were always leaking oil as a normal operating feature. The constant addition of a gallon of oil every 500 miles or so tended to keep the oil on board rather fresh and new. This may explain why it became legend that they only changed the filters on a schedule. I may be wrong but this was one explanation I heard many years ago. Your mileage may vary.

[luvrbus]

I suspect the legend of Greyhound not changing the oil may have been born out of the well known fact that the Detroit 2-strokes used exclusively in their fleet and universally in most all buses at the time were always leaking oil as a normal operating feature. The constant addition of a gallon of oil every 500 miles or so tended to keep the oil on board rather fresh and new. This may explain why it became legend that they only changed the filters on a schedule. I may be wrong but this was one explanation I heard many years ago. Your mileage may vary.

It came about I believe when Detroit were selling the idea on their famous 100.000 mile oil change that cost them millions of dollars on warranty work. I have a couple of the by-pass filters used in  that circus I have removed people thought worked because it was in a antique manual.You need to watch the manuals some say 15/40 oil is recommended, and you use can use anywater for cooling except ditch water     

[windtrader]

Chagen oil = Cheap insurancwe

[luvrbus]

Oil sampling tests is the only way to tell how long of a life span engine oil has in a engine and it will vary from owner to owner and engine to engine 20 bucks for a test is your best insurance 

[sledhead]

It cost me $ 30 for the test with cat and that is a lot cheaper then when I change my oil , a lot less time to do it plus get rid of the old oil

[Utahclaimjumper]

I always figured that oil was cheaper than parts..>>>Dan