I once heard that Greyhound Bus Lines never changed the 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 true for Greyhound in the past or the present?

Rather than taking a chance that could cause a premature and expensive engine rebuilding job, I generally change my oil at around 7,000-mile intervals and whenever I am at a place where it is convenient.  Last year, it took me 12 months to travel that distance. 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 each oil change.

By the way, I attended a Diesel Chassis Maintenance seminar at FMCA rally in Tucson in March and the speaker 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?

Post by: luvrbus 

I have some old service records from Greyhound in Dallas.  Back in the 60's and 70's they had a strict maintenance program.  Oil was changed every 7,500 miles.  They used Gulf engine oil.  Engines were changed at 250,000 to 275,000 miles.  I have seen crankshafts turned so many times that Greyhound had special bearings made that you could not buy from Detroit.

Post by: 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 regularly, they won't like you and do nasty things like turn into oatmeal on the interstate. 

Post by: Gary Hatt - Publisher BCM

Do you mean like this?  

Post by: CrabbyMilton 

Whoa! That's almost as scary as looking at an Insect B movie. 

Post by: luvrbus

With all the additives that are included in oil now, you have to change it out.  My dad and granddad never changed the oil.  They just changed the filter and added a quart of oil in their pickup trucks.  It never carried over to me though.  I never saw a factory oil filter on cars and pickups until 1956.  That was on a V8.  You always had to pay extra for dealer to install the oil filter. 

Post by: sledhead 

I run 100% synthetic oil that I buy on sale. Every year, I take a sample to the CAT guys and get an emailed report. Every time, they told me everything was good, and there was no need to change the oil. I only change the oil every two years. After I changed the oil, my mileage was low, at about 10-12 thousand miles in two years.  

I still sent in an oil sample, changed the filter, and topped off the oil every year. It has been three years now, and I sent in a sample last December (2,000 miles traveled on the oil change). Again, there was no need to change oil again from CAT, so I put another 5,000 miles on it, for a total of 17,000 miles on the oil. Last December, the oil was still a goldish color.  

Here is what some railroads do.

https://cs.trains.com/trn/f/741/t/173471.aspx

Post by: 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. 

Post by: luvrbus 

It came about, I believe, when Detroit was selling the idea on their famous 100,000-mile oil change.  That idea cost them millions of dollars of warranty work. I have a couple of the by-pass filters used in that circus.  People thought this worked because it was in an antique bus manual. 

You also need to read your engine manual which everyone should have. Some say 15/40 oil is recommended, and you can use any water for cooling except ditch water.

Post by: windtrader 

Change Oil = Cheap Insurance 

Post by: luvrbus 

Oil sampling tests are the only way to tell how long of a life span engine oil has, and it will vary from owner to owner and engine to engine.  $20 for an oil analysis is your best insurance.  

Post by: sledhead 

The test with CAT cost me $30, which is much cheaper than changing my oil. It also takes a lot less time to change it and eliminate the old oil.

Post by: Utahclaimjumper 

I always figured that oil was cheaper than parts. 

Post by: Tedsoldbus 

Whether I take two trips or ten a year, I change the oil once a year. I keep hearing oil loses viscosity just sitting in the metal oil pan. I need six gallons of Rotella straight 40W, and I put a bottle of Lucas in at the same time. I do this as it was recommended by three old FMCA guys that were full-time mechanics and my father-in-law, who had a 4106 for 30 years. At $25 per jug plus the Lucas, it can't hurt to do what they said. It is about the cheapest thing I have had to do on my bus such as a new inverter, new fridge, new toilet, all new batteries, etc.

My local Walmart quit taking used diesel oil. Now I have a guy do it. Not sure what to do with six gallons of used oil in my driveway. 

Post by: luvrbus

I don't understand why people are shopping for low-ash oil for the old 2-cycle engine and then adding an additive full of ash that Detroit never approved. 

Post by: Tedsoldbus 

I don't understand any of it, but Gary asked for opinions.  That's why I asked bus mechanics and longtime bus owners what to use and why. Three oil changes after I put in Lucas, my two little oil leaks stopped. Not a drop. I'll run with that.  I've had to replace or repair many things, and I'm trying not to have an expensive engine be one of them. 

Post by: luvrbus 

I use Lucas hub oil.  It is a stabilizer that thickens the oil.  The engine oil comes in a petroleum base and paraffin (wax) base.  I use only Mobil Delvac 1240 petroleum base in 2-cycle engines.  Detroit says to use only the approved oil.  I’ve been into a lot of old Detroit’s and haven’t seen a situation where Lucas helped, but people use what they believe works.

Post by: ProfessionalVagabond 

If you have a Series 60, I think the Mobile Delvac Super 1300 was developed originally for the Series 60. I used to use the Chevron Delo 400 but switched years ago to the Delvac. It's very reasonably priced.  The main reason I changed it is that when you review the engineering content report, the TBN number scores much higher than Chevron and a lot of others and is very close to synthetic. I’ve never regretted it.

I don't use synthetic oil in diesel engines because if you look after them and treat them right, it will pretty much outlive you. Or you will get tired of it and want a new or different one. 

Post by: DaBus

It is a little late here, but I know for sure Greyhound Canada changed the engine oil. My uncle worked at the 'bus garage' in Regina, Canada, in the 60's and 70's. I worked in the truck dealership next door. Greyhound mechanics poured the used oil into the fuel tank, winter or summer. I don't know what the change interval was but the truck dealer recommended 10,000 miles for Cat, Cummins and Detroit at that time. We started using 15W40 in the big cam Cummins in the 70's but remained with straight grade 30 and 40 in the Cats and Detroit’s.