Oil Change Interval

Just my opinion - If you don’t do any type of oil analysis how do you know your oil is bad? People who are afraid that they will ruin an engine if they don’t change their oil every 10, 20, or 30K could have severe engine problems and would never even know it. I have a Paccar. The manual says change oil every 60K. I do an oil analysis at 30K and change the filters (probably unnecessary) to make sure everything is fine then I will change the oil at 60K and send in a sample again to make sure everything is still ok. You NEED to check for fuel dilution, soot content and wear metals every 25-30K miles so you know when something is not right - like coolant in your oil (head gasket) or too much fuel in your oil (injectors) etc… Just changing oil at shorter intervals accomplishes nothing and you have no information on what is happening inside that 30 thousand dollar engine.

 

I agree but disagree.

15k miles is around 250 hours give or take. 30k miles is around 500 hours. 250 and 500 hours are the two most common service intervals on heavy equipment and engine oil analysis picks up abnormalities just fine on those. I see no reason why it would not work the same way with a truck engine.

 

That's the intervals that Ryder normally changes the oil on their tractors. So if it still running with no issues...why switch now?

 

I know y’all are talking newer motors. I have an older one hence my original comments. I still say I would never go past 30k even if I had a newer engine.

Even with good oil analysis at 15k on an older model engine there is no harm in changing the oil at that point. I know some use oil analysis as a method of extending oil changes until a later date. I use oil analysis as an indicator of possible engine issues and change the oil anyhow. It is not that expensive relatively speaking. But hell even with great oil analysis you can shat a motor tomorrow.

 

Oil in diesels does not have to be changed like that of gasoline engines because diesel fuel lubricates whereas gasoline does not. Seems like changing diesel engine oil every 25k might be fine.

 

Did oil analysis at 30 K newer Cummins. Came back oil is in great shape. Don’t go into an operation blind. Intel is everything. Switching to a higher grade oil and going to retest after 35K and up until I know where my interval stands.

 

I oil change all my trucks at 12-14k miles (once a month). Everyone I know does it under 15k miles. I chose this interval because it matches me being home, and oil changes run me $260. Also my trucks are pre emission old except one. I have a diesel pickup as well and it says every 15k but I do every 7k. Probably a waste but you never know.

I remember working for a company a decade ago and they did oil changes every 75k miles. Big companies just sell the trucks so they have nothing to worry about.

 

I'd trust the manufacturers recommendations personally. Use the type/viscosity and interval they specify for your operations. The may use hours instead of mileage or a combination of the two as barometers.

 

It lubricates the bearings, rockers, turbo, geartrain, and compressor?

It doesn't even lubricate the cylinder walls, and if an injector is leaking, it washes the cylinder. Diesel fuel is a terrible lubricant. If anything, it's a solvent.