Oil filter change vs oil change

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After contemplating on the issue, since this thread got brought up, I’m going to start doing 10,000 mi oil changes and 5,000 mi filter changes in my two 2.0 VW diesels. They burn about 2 liters every 10,000 miles (typical for the TDi). As I add in oil every couple thousand I am putting additives back in. Filters are cheap and it’s a top mount cartridge element so it’s very easy to change and isn’t messy at all.
I’ve always been a little skeptical of the 10,000 mile oil change. This will at least make me feel better about it.
I’ll keep it business as usual for the classics though.
 
When I worked on Mack Trucks in the 80's,3 oil filters, 56 quarts of oil,25,000 mile intervals.
 
I am a scientist/biologist by education and a dentist by profession. How is this for science? Why is it that dental insurance companies pay for 2 checkups and 2 cleanings every year???? Because a tooth paste company back in the 50s came up with a marketing campaign that said to brush 2xday for 2 minutes and see your dentist 2xyear. The famous 2x2x2 from pepsodent toothpaste. An insurance company said (paraphrasing here), "that sounds like a great idea". Thus 70 years later that is the accepted "norm" for dental care.

Compare that to modern oils, filters and automotive maintenance and you get the "change your oil every 3000 miles and your filter while you are at it after a hundred years of automotive service. I guess you can complicate it by having old technology vehicles and modern chemicals and confusion prevails.

I guess that is why much of what we do to is because that is what dad did and his dad before that. Thanks for the replies.
 
Some of the big lubricant companies advertise extended drain intervals. The one for which I worked 32 years always refers to the vehicle manufacturer recommendations. Long ago I asked a senior manager why this was so. His response was that anyone saying their motor oil could be used beyond the OEM drain interval was assuming the vehicle's warranty.

I handled the field work on many oil claims, but we never paid one. The samples were almost always contaminated with fuel, coolant, dirt, or other's products. Or, not our product at all, or nothing wrong with it, good to continue to use.

We did pay one filter claim, out of the hundreds of thousands I sold. It failed, and dumped all the oil as the car left my customer's parking lot. They just wrote a check, covering all repairs and expenses, like the rental car and taxis. The filter was a private label Purolator *I think.* Every several years we switched between them and Fram. We owned Purolator for a while in the late '80s into the '90s, and switched from Fram then, and continued to use Purolator for awhile after they were spun off. I was told the cost of the claim was built into the price of the filter, because they knew one in a million or so would fail. They could reduce those odds, but not at the price point of less than $2.00, which was a very normal wholesale price for the majority of filters sold 25-30 years ago.
 
I thought about skipping a filter change. I usually cut open the oil filters. My Dakota, i put 60k on a 4.7, sold it at 220k. My ram 5.7 ive had for 15k miles, 158k. My daughters cherokee 4.7, shes put 15k on it, 167k.

What ive noticed, when ive bought them they had cheap no name filters on them and had gunk in them. The oil was always dark. I alway use full synthetic. At the first change the filters had some black debris but nothing too concerning. On the Dakota i did 2 rounds of sea foam in the oil. 1st time scarred the hell out of me. Metal crap black chunks and there was a tic that eventually went away. Never did seafoam to my daughters jeep, hers burns not even a half quart every 5k. After a couple of oil/filter changes the filters seem in all the vehicles seem relatively clean. So I thought about skipping a filter change...but then if figure their only $8. Cutting them open has given me peace of mind...

(if you wondered, after the 2nd sea foam on the Dakota, just some black slime, more than usual. I waited a year or so between sea foam. Truck ran great.)
 
As mentioned above, the base oil doesn’t wear out if it’s synthetic. The additive package does get consumed. How quickly it gets used depends on way too many factors to say there is any relationship between miles driven and oil change needs. The only way to know for sure in any application is to send an oil sample in at an arbitrary mileage to start with, like 3k miles and have it analyzed. Once you get the results you can see what’s left of the additive package, plus other details like fuel and coolant dilution and any bearing materiel and such. That’s the only way to know how often you should change your oil. Of course the oil that is used will also be a big factor in how often the oil needs changed. Some oils use the bare minimum additive package to make the grade.

FCA now has an algorithm that calculates based on miles driven, engine peak and average RPM, oil temperature, time spent idling, etc to automate the "oil change required" light.

I'm sure other makes do as well.

So far it's been within a few hundred miles of 10K for my true mixed driving with occasional "sprited' bursts.
 
My opinion …..
Oils do break down over usage time and the viscosity changes.
And a lot of dirt comes thru Crank Case Ventilation especially if not pulled from the inner air cleaner.
But I’m not an expert. Just an old man with limited experience and internet access.
 
The oil change interval for my 1965 Barracudas 273 was 7,500 miles in normal conditions and a every other filter change.. That was with 1965 Dino oil spec's. Oil has come a LONG way Baby since 1965.

Our 1998 Buick 3.1 V6 had a Change oil system light that NEVER came on. Just once I ran the oil out to 10,200 miles and the light never lit up and I chickened out and dumped it. Spec oil was 5W30 but its life was 7,500 miles and dump with new filter and almost always Delo 400 15W40 and it made it to 355,000 miles when the trans let go.
 
I recently changed the oil and filter on my 2000 Buick Park Avenue with the supercharged 3800 V6 after about 3200 miles. I noticed the "oil life indicator" was only at about 50%. Since it has 150k miles on it I figured going with the old 3k-mile interval would be better but I did notice the oil was pretty clean and not much smell to it, also not super watery like would happen when I changed the oil in my 250k-mile Jeep 4.0L straight-6 (which I have a gut feeling runs the oil very hot, next one I get will have an oil cooler added).

I guess I'll try moving up to 4k oil change intervals on that car, it leaks/burns about a pint every 1500 miles or so anyway so I end up adding fresh oil before it's due for a change.

Here's some food for thought from guys who actually do regular maintenance and repairs on both gasoline and diesel engines, new and old... One of my favorite channels btw, Rich is a super cool guy I hope to meet him some time in real life.



 
I use Valvoline syn blend in everything except the 2015 Renegade which requires "Ferrari spec" Euro syn oil.
 
Any known 'SLUDGE' engine needs a few mods to keep the oil from gunking up the valvetrain. Somehow the oil gets trapped up in the heads and valley due to piss poor engineering. Those you MUST change the oil at 2,500 or so but that only helps a fraction.

All Jeep 4.0L run hot due to piss poor designing. The radiator is too small for one. The head traps air in the rear of the head and you must lift the rear end up high enough to get that air to 'BURP' out. The coolant overflow system was designed in a Kindergarten class. And if you do the 4.2's crank swap for a stroker 4.5/4.6/4.7/5.0 Liter that heat is even worse. You should add an oil cooler with its own fan and thermo switch.

The 5.2 and 5.9 Magnum's oil pumps SUCK, no pun intended. The bypass valve sticks open when real hot and as you are doing 70 MPH, the idiot light comes on and the crank is eating bearings. Does not matter what type oil you use. Drop the oil pan and put a Melling HV pump in. Where the type of oil matters is sludging in the heads and lifter valley. Hot oil gets trapped and bakes. After replacing the crap oil pump, add an exterior oil cooler.
 
I agree with Rusty.

I've always been a 5000 mile or once a year guy since the 1980's.

Now even FCA recommends "when the oil change light comes on OR not to exceed 10,000 miles".

IMO changing at 3K is throwing money (and time) away.

Yup, I just changed the oil in my '16 charger and the computer is already nagging me to change it again. About 97 of every 100 miles is highway driving, so I just change both every 10k miles, that comes out to three times a year.
 
Don't know why you could contaminate new oil with old oil in the filter. Filters are not that expensive...
I've always changed my oil once before the next filter and oil change.
The oil is always clean.
I change my oil for hours run usually 10 -15
 
We all know that oil will not last forever, or that an engine will not last forever without clean oil. What I cannot find is information about oil changes and oil filter changes. Yes, I have separated the 2 options.

What does the science say, not just someone's opinion? We have all been told to change the filter every time you change the oil. OK. But would the oil last longer with a filter change at say 2000 miles, ( if the recommended "oil change is 3000 miles")? Could you go 6000 miles before oil change when you change the filter every 2000 miles and still have good oil properties??

I guess you could also ask the opposite question. Can you change the oil and leave the filter?

Again, has there been any studies?

I could see using a non-bypass filter and watching the normal oil pressures. Whenever, the normal, say 75 psi, at 2500 rpms begins to drop, change the filter. Whether it is at 2000 or 4000 miles. and then change the filter at whatever interval you think is appropriate.

Finally, with many of our cars, the oil degrades by condensation and simply sitting more than use. How does that affect the oil filter and oil properties?

I guess I have too much time on my hands and I am probably thinking too hard about this. But, maybe someone has pertinent info on this.
I was a while back thinking along the same lines, mainly to reduce the frig factor of chancing the oil filter, my solution below.
Im Looking for the hardware to have 2 filters. 2 for one, double filtration and instant frig free accessability

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Years ago(late 70s early 80s) my dad bought the AMS-oil bypass filter. Worked fine???? Till one of the lines broke and my mom set off to drive 35 miles to LA.

When my Dad saw the oil trail in the garage and down the road he hopped in the Dart and finally caught up to my mom.

Luckly he got to her before her mustang ran dry. He removed it the next day.

"The parts you don't add, don't cause you no trouble!"
 
Years ago(late 70s early 80s) my dad bought the AMS-oil bypass filter. Worked fine???? Till one of the lines broke and my mom set off to drive 35 miles to LA.

When my Dad saw the oil trail in the garage and down the road he hopped in the Dart and finally caught up to my mom.

Luckly he got to her before her mustang ran dry. He removed it the next day.

"The parts you don't add, don't cause you no trouble!"

That Amsoil Bypass filter set up has, last I knew, been running fine on my neighbors Ford Dulley V8 for over 300,000 miles last I heard10 years ago.... He used the Amsoil hose kit. I think he added two 45 degree brass connectors so the hoses were flush to the inner fender and supported and did not stress any angles. YMMV
 
Any known 'SLUDGE' engine needs a few mods to keep the oil from gunking up the valvetrain. Somehow the oil gets trapped up in the heads and valley due to piss poor engineering. Those you MUST change the oil at 2,500 or so but that only helps a fraction.

All Jeep 4.0L run hot due to piss poor designing. The radiator is too small for one. The head traps air in the rear of the head and you must lift the rear end up high enough to get that air to 'BURP' out. The coolant overflow system was designed in a Kindergarten class. And if you do the 4.2's crank swap for a stroker 4.5/4.6/4.7/5.0 Liter that heat is even worse. You should add an oil cooler with its own fan and thermo switch.

The 5.2 and 5.9 Magnum's oil pumps SUCK, no pun intended. The bypass valve sticks open when real hot and as you are doing 70 MPH, the idiot light comes on and the crank is eating bearings. Does not matter what type oil you use. Drop the oil pan and put a Melling HV pump in. Where the type of oil matters is sludging in the heads and lifter valley. Hot oil gets trapped and bakes. After replacing the crap oil pump, add an exterior oil cooler.

Good to know, when I rebuild my 4.0 it'll be stock stroke but I may turbocharge it (with forged pistons and beefed rods). I did always feel like the radiator on my XJ Cherokee was a bit small for an all-iron 4.0L straight-6 designed in the 1960s. I overheated it many times while offroading until I installed an aux electric cooling fan; apparently since mine was a manual trans with no A/C it only got the engine-driven cooling fan from the factory which only pulls on half the radiator core. Might have some design flaws but the thing is so damn bulletproof it can take being overheated and run with dog-piss in the oil sump lol. Mine started having weird oil pressure issues likely due to me revving it to 4500 RPM on a regular basis, pretty sure the con rod big ends got ovaled and the bearings are bad. But that Jeep got totaled from being rear-ended a few months ago so the engine is now in storage.

On the subject of the cooling system, the heater also sucked lol. Might be because with no A/C it didn't have an air-recirc function so it was always pulling in outside air but that thing wouldn't put out heat worth a damn basically until the thermostat was opening. And I did a lot of maintenance and small mods to the cooling system to increase flow (took out heater control valve and replaced with higher-flowing brass ball valve, added Water Wetter to coolant). Got it working better but still sucked compared to my other vehicles.

Back on the subject of oil, I am curious about doing an oil analysis on my vehicles. Would be nice to confirm with actual data that I can extend my oil change intervals past 3k miles. And same as @YY1 I run Valvoline full synthetic in all my engines (Duster has a roller cam so it gets the 5W-40 Euro-spec MST stuff), good price and IMO better than Mobil 1. Supposedly Pennzoil is a lot better than it used to be but I don't feel a need to switch when the Valvoline FS has been serving me well for over a decade.
 
Good to know, when I rebuild my 4.0 it'll be stock stroke but I may turbocharge it (with forged pistons and beefed rods). I did always feel like the radiator on my XJ Cherokee was a bit small for an all-iron 4.0L straight-6 designed in the 1960s. I overheated it many times while offroading until I installed an aux electric cooling fan; apparently since mine was a manual trans with no A/C it only got the engine-driven cooling fan from the factory which only pulls on half the radiator core. Might have some design flaws but the thing is so damn bulletproof it can take being overheated and run with dog-piss in the oil sump lol. Mine started having weird oil pressure issues likely due to me revving it to 4500 RPM on a regular basis, pretty sure the con rod big ends got ovaled and the bearings are bad. But that Jeep got totaled from being rear-ended a few months ago so the engine is now in storage.

On the subject of the cooling system, the heater also sucked lol. Might be because with no A/C it didn't have an air-recirc function so it was always pulling in outside air but that thing wouldn't put out heat worth a damn basically until the thermostat was opening. And I did a lot of maintenance and small mods to the cooling system to increase flow (took out heater control valve and replaced with higher-flowing brass ball valve, added Water Wetter to coolant). Got it working better but still sucked compared to my other vehicles.

Back on the subject of oil, I am curious about doing an oil analysis on my vehicles. Would be nice to confirm with actual data that I can extend my oil change intervals past 3k miles. And same as @YY1 I run Valvoline full synthetic in all my engines (Duster has a roller cam so it gets the 5W-40 Euro-spec MST stuff), good price and IMO better than Mobil 1. Supposedly Pennzoil is a lot better than it used to be but I don't feel a need to switch when the Valvoline FS has been serving me well for over a decade.

Just saying, Use the 4.0 pistons and the 4.2's rods and crank is an easy 500cc's more with no over bore. The 4.0 has a bigger bore but shorter stroke than the 4.2... A 0.060" over bore is a 4.7L
 
Just saying, Use the 4.0 pistons and the 4.2's rods and crank is an easy 500cc's more with no over bore. The 4.0 has a bigger bore but shorter stroke than the 4.2... A 0.060" over bore is a 4.7L

I know, there are tons of Jeeps around here with stroker motors, thing is I don't want the powerband to fall off a cliff after 3500 RPM and because we have emissions testing here I'm very limited in camshaft choices, also don't feel like trying to port the head beyond the usual cleanup. The stock 4.0 had more than enough torque to pull my Jeep up super steep inclines in low-range and driving on the street I could take off from a stop without touching the gas pedal if I wanted to. Gobs of grunt from idle to 4000 RPM.

Living at high elevation I'd rather keep the low-end torque the way it is and have a turbocharger with maybe 8-10 psi boost to give the extra power when driving on the highway up the mountains or just ripping around on the street having fun. ~300+ HP in a 3000-lb 4x4 SUV is a lot lol. Off-road you really don't need much power at all, it's all about the gearing from my experience. 4.0's love boost, much like a slant-6 they take to it very well and even in stock form hold up for a long time as long as the boost doesn't get cranked up super high and the tune is good. Yes it'll be more work than building a stroker engine but at this altitude forced induction engines sh** all over anything naturally aspirated unless it's got mega cubes and compression. The 360 in my Duster would make over 350 HP at the wheels at sea level but up here at about 5300' it put down 286 uncorrected.
 
Do people actually spend $$$$$$ to build or (have built) a performance engine, being methodical and careful on assembly, worry about break-in, long Engine life, only to concern themselves with long oil and filter change intervals? Mileage smileage. It’s how the engine is used and not used. It starts “looking like” and “smelling like” and it’s dump time.
 
I did not know you could BUY a "non" bypass filter, and would not. It is a safety factor. Regardless of how dirty the filter gets, "what happens" if on that 8900 RPM shift (or whatever) the filter cannot keep up with pump flow? Is it going to split the filter?
 
Many years ago, back around 2005, I read a thread or article that detailed about 200k miles of oil analysis on a very frequently driven corvette that was a 2000 or 1999 vintage. Owner/driver was having the oil analyzed and adhering to the extended drain intervals and oil change light rather than a standard change schedule.

The short version, from my very fuzzy memory, was that you should change factory oil almost immediately. After that, go 2-3k and change again. After that, 10-15k wasn't abnormal, and oil consumption seemed to outpace wear of the oil - at least with highway miles. The oil filter tended to pick up more junk in the first half of its life than the second half, but more frequent filter only changes had so little effect on the oil analysis that waiting for the normal interval seemed fine. Once consumption went up, with mileage, and oil had to be added in less than 10k miles, the analysis showed a significant improvement in oil quality at the time of change. To the point that if an engine could take more than a quart or two between changes, you could effectively just change the filter and keep going.

Take it with a grain of salt, but those are the key take aways I remember. Seemed to make sense, and it's not for nothing that it was a fuel injected vehicle driven mostly on the highway and no track time from what I recall.
 
You need to consider how a vehicle is driven also. Lots of short trips and the oil will degrade a lot faster.

I have a 5.9L in a 2001 dodge ram that I regularly take 60 miles to work and back. It has 210,000 and still has 40-60lbs of oil pressure. I've had it over 10 yrs and change the synthetic blend oil every 5,000-6,000 miles.

Now if it would just get better than 12mpg!!
 
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