just occured to me that all our big cummins N14s go out 30k miles at a time between oil and filter changes. this is using the exact same valvoline premium blue 15w40 i use in my truck, only difference is the filter is about twice as big. my little cummins doesn't work nearly as hard, but according to the manual i have to change at 7500 miles. thoughts?

 

10000 for me....

 

15,000 miles between oil/filter changes.

 

Maybe its because they hold about 28 gallons more than our trucks!

 

Yes, it's totally due to the oil capacity.

jh

 

LOL , the N14 holds 11 gallons including oil filter... oil has a coupla jobs to do while it is in the engine , cooling , cleaning and lubricating are the important one's. I think your streching it at 30,000 miles on the N14 , most fleets are going 10,000 to 15,000 miles. I change my oil at 15,000 and use the Extreme Valvoline oil.

 

I dont see why you need to go 30K

for oil changes, I hate pushing my truck beyond 5000 for an oil change, but if i cannot afford it, I will go 7000 before no more, (aint done that yet tho) I have heard yet havent tried this, partially drain your oil and add new oil to that old oil (why tho?) and change your filter.. Id rather cut the rest of it and do a complete change

Tx

 

mine i change every 8K my excursion i changed every 10k cause excursion had more oil capicity

 

The n14 plus holds 11 gallons including filter. I must be really tired because I was thinking of a totally different engine. I was also thing of quarts, not gallons.

Also on the new n14 plus they have an advanced engine oil managment system that allows them to go over 500,000 miles between changes. Wouldnt that be nice?

 

Never mix new oil with old. That's like saying you can add good cheese to moldy cheese and end up with a final product that is good to eat. The new oil will be contaminated by the old oil and will not be able to do its job correctly.

By the way, when I bought my truck it had already had the oil changed at 4000 miles. I had a free oil change coupon and had it changed again at 11,000 miles. I just changed it last night at 20,000 miles, and let me just say that after seeing the oil, I will never go 9,000 miles before a change again. I'm going to change it at 7,000 and see what it looks like.

 

I strongly disagree.
Adding new oil to old oil is exactly the way the well proven for a decade Cummins Centenal system that allows 500,000 between oil changes works.
Adding new oil to old is also the main reason people can get away with extended oil changes with synthetic oil and bypass filters. The make up oil added when changing filters is enough to sufficiently replenish depleted oil additives.
Cheese and oil are two different things.

 

we've been running 30k intervals on this oil and engine for as long as i can remember, never an oil-related failure since we started running this engine in the early 90s. we have a few over a million miles. oil capacity didn't occur to me, makes sense.

 

Change your oil by time rather than mileage. Sample at 7500, 10000, 12500, 15000 and see what interval your driving habits are working at.

 

The guy I buy my Amsoil from claims he's got around 70K on two oil changs. The dino thats in it from the factory and then 7k later the synthetic for the rest of the time. It's a 01 or 02 CTD. He says he changes the filters (got two in a remote setup) around every 7 K and draws a sample and has it analized. Makes sense to me. Would I do it no... Oil is much cheaper than iron. Just my .02$ Jethrro

 

Yup the Centinel system has been around a long time , but no longer available and outlawed in many states, the N14 has been out of production about 2 years now , also no longer available, and replaced by the ISX. if you go 30,000 between changes, I will say that is amazing and no problems , there is a fleet out there now called PMT that does the same thing and they have more problems then most with cam bearing and main bearings. and talk about stinking oil mess when doing anything on the engine. but the main corporate office want to save money, the only engines I would take to that limit is the Natural gas engines. they simply burn cleaner and use ashless oil.