JBradley500

I run 3 gallons of conventional valvoline blue and a quart of lucas additive... ive got about 4000 on it now and need to make a 700 mile trip home next weekend. I will change it once i arrive.

Typically id change it now but I was wondering how long you guys go normally. I dont want to come back and have 1500-2000 miles on new oil in a week or 2 already if i dont need to. 700-1000 is bad enough!

Not a real good tech question, more of a way to see if im pushing it or not.

infidel

I did 5k mile changes for awhile till I did oil analysis and found my Delo 400 was still good to go at 12k.
I settled on 10k changes, easy math
Motor oil quality and properties have improved tremendously in the last decade since the service schedules were written up for our old 12 valves.
That's why the new Cummins engines can go 15k between changes, it's better oil, not better engines.
The auto industry has been pressuring the lube manufacturers for longer lived lubes in an effort to offer a vehicle that only needs to be serviced every 100k. Idea is that most folks will trade in their rig before it needs any service.
The manufacturers never got even close to 100k oil but at least increased engine oil life threefold or more.

JBradley500

i do agree that new oil is the cats pajamas... but, my truck puts soot in the oil. im more worried about the soot than lubrication ya know?

infidel

Diesel engine oil is designed to hold soot in suspension rather than deposit it as sludge.
Big reason why it's bad to use gasser engine oil in a diesel.
It doesn't take much soot at all to turn the oil black. All of the diesels I own have black oil within an hour after a change. Even my new JD tractor had almost instant black oil after it's first oil change.
If you're concerned about soot change the filter more often but keep the oil.

JBradley500

ok sounds good... maybe ill just run it for a few hundred more. i didnt realize soot contamination was such a common deal. i figured my trucks smoke habit was causing it.

DragonSlayer

I start thinking bout changing oil at 7500 miles, and try to do it by 10000 miles. Just where I feel like it. After seeing trucks at work go way more than that with clean oil analysis, I don't worry much anymore.

67HotRod

At 5k i change the filter and replace both oil/filter at 10K.

Rare1

I use Rotella Synthetic 5W-40 and change it once a year whether it needs it or not. Usually 8K to 11K miles. I have had several used oil analysis reports and they are all the same, the oil is not depleted, no metals.

whereswaldo250

I run Valvoline's Premium Blue and I change it about every 5K (or every 6months) that seems to work for me, oil still has a golden hue to it. I'm thinking about getting an oil sample done at CAT for this next oild change, just to see.

Midnite

When I had my 1992 I also did 10k mile changes based on oil analysis results first using Rotella T, and later switching to Delo 400.

4 - 5k miles is a pretty short interval, especially for a good synthetic oil.

TxDiesel007

i used to go 5k miles between changes on my 12V

now i go 10K on my CR..

only thing that stays the same, i use baldwin filters and rotella 15W 40

its been a good combination for me

LGarrison

I change my oil at 10,000 miles or three weeks which ever comes first.

jockybox

Used to work for a company that was developing a technology called "Ferography". It was an oil analysis system that used magnets, gravity, microscopes and training. The setup cost and training made it very expensive to get started so it was a tough sell. It did tell you everything you wanted to know about your oil.

I did learn a lot about oil and how oil deteriorates. First, the oil we tested under normal conditions would go hundreds of hours beyond the manufactures recommendations. This was in engines running for long periods, like long highway trips. When we started subjecting them to conditions like short runs, say less than 3/4 of an hour the oil contamination went a way up. The biggest increase was in carburetor gas engines, then fuel injected gas, then diesel engines.

The main problem with the gas engines was gas contamination. The engines were not running long enough at hot temperatures to get rid of the raw gas that gets into the oil pan. This really was not much of a problem with fuel injected engines.

With diesels the main problems were glycol contamination and dirt getting through the air filter. If you drive in a lot of dust, change that air filter. In all cases we tested if the oil filter was changed the oil contaminants would drop below the manufactures recommendations. Once we seen glycol contamination in the oil we new it was not long before there was catastrophic engine failure.

The thing I really learned was the value of synthetic lubricates. I was driving a Jeep with a 351 in it. The recommended oil changes was 3000 km. Using synthetic oil and changing the oil filter I went up to 30,000 km and the oil still tested OK. I changed the oil filter at 15,000 km and added a little less than two liters of oil. This truck was never driven for short distances and them shut off. It started at -45 without being plugged in, and when it starts there is oil pressure almost immediately.

My present truck, a 97 Dodge 2500 with a 12 valve, has had Petro Can synthetic oil in it since 20,000 km. This was my work truck and it spent more than 50% of it's time on dusty or muddy gravel roads. Much of the time it would be in 4X4. I changed the oil and filter every 10,000 km when working and increased to 20,000 km when I used it on long highway trips. The engine was always run for at least and hour after reaching operating temperature.

I have put over 500,000 km on this engine and only had three problems with it. Replaced the water pump(the only time it let me down on the road), replaced a starter, and at 12,000 km the injector pump was sent away for repair. That was a good thing because I got an additional 200 km out of a tank of fuel.

Two things that I think helped was the use of synthetic oil and the installation of a pre-heater. With the synthetic oil I could start the truck at temperatures down to -25C, if I plugged it in it would start down to -40C. Now with the pre-heater it has started at -55C with no problem and in all cases the oil pressure is up in less that 10 sec.

After a break-in period I use synthetic oil in everything I own. In gas engines I use Castro 0W-50W when I can get it, otherwise I use Castro 5W - 30W, or whatever else Costco sells at the moment. In the diesel I will stick with Petro Can synthetic. In any case I double the intervals between oil changes so synthetic is no more expensive than regular oil, but you get better cold weather starts, and more stability when it is hot.

dc10freighter

At 300 miles after my oil change the oil looks new, At 3000 miles my oil doesn't look much different than a poorly maintained gasoline car. For me oil is fairly cheap compared to the pain it is to R&R an engine.

oliver foster

I have been doing 10,000 mile intervals with my 24V using Valvoline full synthetic blue.
I use this because in the winter it starts better [gets -35* here] with the synthetic oil and I think it is better for the long oil change interval.
My other summer only cummins rig I change once a year with Rotella 15W 40 as it never sees towing, hard use, or super cold winter starts and gets only 5,000 miles a summer put on it.