I always change my oil and filter every 3000 miles, but would it hurt to let the filter go to every other oil change?

 

you can do whatever you want. BUT for the couple bucks it will cost you for a filter, why take the risk?

 

Oil filters are easier to change than engines

 

YES

 

With the quality of oil that is out there now, especially the synthetics, you don't have to change every 3,000. You can probably squeeze 4,000 with no problem. But you do want to change the filter everytime you do it.

 

good *** yes. changing the filter is more important than the oil change.

 

Yes, what zippy said. If you want to skimp, just change the filter and add a quart of oil--you will be better off than doing it the other way.

 

Brad,

Of course you don't need to change the filter every time. And you don't even need to change the oil every 3,000 miles either. And you can skip the trans oil changes every 24,000, and forget about greasing he front end and lubing the body mounts and seals. Never mind checking the air in the tires. Front wheel bearings don't HAVE to be repacked every 24,000 either. You can skip changing the differential oil every 30,000, too. And don't worry about the front end alignment, it'll be fine. Don't even think about wasting your time changing belts and hoses, or even the coolant every two years.

Maintain that schedule, and you'll be driving what most people call a "Honda" - and everyone knows that's the finest example of automotive engineering on the planet.

Zippy and '82 are absolutely correct. If you're really broke, change just the filter and add just a quart of clean oil. You'll be better off than ignoring the filter.

 

Okay, I've heard reports (mainly from one of those who has posted a reply on this thread) that Dino oil actually starts to break down at 1000 miles. So, why does the same person say change the filter, not the oil?

Next point, many, many, many folks change thier oil and filter at 6K miles, they also report many, many miles on thier engines without issues (a search on "oil" in this board will yeild milage numbers).

My point? I dunno, just babbling on. I'd say change the oil first, worry about the filter later...if I had my druthers...why? Well heck, when was the last time you ever had a oil filter plug, or have the engine run in bypass? Probably never, certainly not in even 10K miles of "normal"driving..unless maybe if you lived in a dustbowl.

I think people get way to **** on oil changes, todays oils are mcuh better at protection than yesteryears oils, when they started the 3k recommendation on changes.

Heck, my latest purchase of the "finest example of automotive engineering" says 5K adverse conditions, 10kmiles normal driving conditions...and they threw in a 100K miles warranty for free...Hmnn, is it really necessary? they don't think so, they're also willing to back it up. Other thing is they'll extend the warranty (as all other manufacturers/warranty places will do) for a modest cost when the original runs out.

Again, the point of my ramblings? I dunno...as I mentioned before, just rambling...must be those "everyone's internet" commercials I keep hearing.

I guess if you're too hard up to spring for 3 bucks for a filter, the 6 opr 8 bucks for oil is probably harder to shell out too...strecth you changes out further...engine in good tune, not running rich shouldn't contaminate the oil severly anyway...and if it's true that the oil does indeed break down at 1000 miles..what another 4 or 5K miles anyways?

I'm done, havn't posted for a few days, guess I used all my bandwidth allocation up in this post. Gonna go soak the finger tips in ice water.

 

I just want to ask you

do you change the toilet paper in your hand each time you wipe your ***?

 

Actually it should be the other way around, it's more important to change the oil, believe it or not a dirty oil filter will filter better up to a point because as the filter gets dirty it starts clogging up and that will let it start trapping smaller and smaller particles that are suspended in the oil, these same particles will pass straight through a new filter and increase engine wear, I was reading about this awhile back and some trucking fleets only change filters every 2nd or 3rd oil change because they determined the engines last longer that way. But I still change mine every oil change.

 

Toilet paper? Be a man, use a toilet brush...after you've accomplished that, we'll talk

 

Corn cob buddy!!!!! Just like in the good old days!!

Swish it around in the water a little, and hang it back up.

Seriously though. I change my oil whenever I'm bored. I don't drive enough to surpass the 3K mile mark, so I just change it for something to do, as well as the filter.

Sometimes it goes ~3500 or so, but I dunno. I guess it's different when I know I got a 350 in my garage to drop in whenever the 305 pukes!!!!!!

Just an FYI. My buddy has a 89 Camary that has about 250K miles on it. He bought it new. He changed the oil about every 8-10K miles. And he's always used dino lube, not sympathytic.

AJ

 

Je$us Chri$t calm down the only reason I asked is because I thought I had a filter at home, but when I got back with my oil I found that I didn't. Don't think that I don't take car of my car or neglect it. I baby it and maintain it religiously. I was just wandering if I could get away w/ out changing the filter this time because I didn't want to drive 30 minutes to go back to the parts store. Rest assured I know how to take care of my car, and FYI i'm changing the filter tommorrow.

 

When the filter gets full of crap(and they do between oil changes--everyone I've taken apart), they bypass or force the particles through the media. High capacity filters in fleet trucks(or regular filters in fleet trucks) don't apply. Putting 4 quarts of clean oil in with 1 quart of dirty oil and a dirty filter is a waste.

 

I'm calm,just a smart ***

and yes you can do it though it is best to just change the filter if you can

that way you have the cleanest oil you can get

though by doing it this one time you are not going to kill the motor or anything

 

Brad,

Apparently some of us misunderstood the question. The way your first post was worded it looked to me like it was going to be a habit. My bad.

If this is just a single-occurrence anomly thing where you don't have a spare filter on hand, remove the old filter, dump as much of the dirty oil as you can, then reinstall it TIGHT (remember that the gasket probably won't swell any more to seal leaks). Refill the sump with clean oil and get a different filter at the next change (or tomorrow, if you want). If it isn't a habit you probably aren't going to hurt anything.

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8Mike9,

Actually, any lubricant will start to break down immediately on use. The molecules begin to crush and break up into somewhat shorter chains. This is not a really bad thing, especially in mineral oils where the molecular lengths can be very random. The problem with mineral oils is the additives that are supposed to enhance the oil and prevent it from doing what any mineral oil tends to do. These additives start breaking down pretty quickly, and don't recover. The polymers that coil and uncoil to enhance the thermal stability get broken into smaller chains as well, and don't do much high-temperature enhancing any more. After about 3,000 miles of "severe" driving (the kind the average driver does) the additives are spent to the point where they don't offer any benefits to the oil, and you're left with a straight-weight mineral oil with no acid protection. That's time to change. Obviously, oil that is treated to a better than "severe" life will last longer.

Synthetics don't break down nearly as quickly, and have fewer additives to be sacrificed to protect the oil, so inherently last longer.

Granted, any particulates that are generated need to be trapped by the filter or will contaminate any lubricant to the point of uselessness, regardless of what the base lubricant stock is made of. That's why a good oil filter is so important.

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DartByU,

You realize that most larger trucks have at least two oil filters in full-flow, possibly a drier (adsorption filter), and have 13-16 gallon (not quart) sumps. The oil stays a lot warmer and drier than in an auto engine, and the filters are about as large as a small Toyota. This is one of the nicer things about some of the Porsches - they really pay attention to the filtration and oil cooling. More "****" Deutschelanders.

I'm just basing my opinion on almost two decades of amateur lubrication engineering and analysis for industrial equipment. I was one of the first in my area to use synthetics in air compressors in 1984, and I was considered "goofy" for "wasting" the extra money on the oil. When my 200HP screws were still running 11 years later (after most people had changed air-ends at least TWICE), I wasn't so "goofy" any more. The last 125HP Kaesser screw compressor I got requires synthetic lubrication - or no warranty. Just like some auto engines. Go figure.

When the oil spec has to have particulate counts of less than 16 for 1.0 micron solids, you end up changing a lot of filters to keep the "old" oil that clean. In fact, the new "clean" oil that is used to fill the sumps has to be prefiltered for a couple of days to get it just barely clean enough to put into the system.

Some of us do particulate counts and oil analysis on removed engine oil too, just to see what's happening in the engine. Call it **** if you want, that's me...

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That's fine with me. I'd rather have a hundred "Smart-asses" like you around than just a handful of "dumb-asses". Good thing this isn't a Mustang board, or I'd be frustrated for sure...

 

Vader,

Couple of questions, if you can spare the time...

You mentioned your compressors lasting at least twice as long...was the oil change intrevals you used, the same as the others? Or were you able to stretch the intervals with synthetics and achieve those results?

I'm kinda trying to draw some type of conclusion (similar to the AMSOIL-type claims of 25K or 1 year changes) using synthetic...i/e change it as often as you would regular oil and the engine (all things being equal) *should* last twice as long before clearances are OOS, or can the change intervals be twice as long and the engine last the same?

What's your opinion?

Secondly, what do you feel is the biggest factor of engine oil breakdown...defined as "not being able to lubricate the rotating/moving masses at all engine RPM ranges"?

Last question (not sure if you studied this aspect with IC engines if your feild of study was limited to driven devices), but can an airfilter effectively keep particulates from entering the oil, past the recommended oil change interval? Reason I ask this question is some say the biggest oil contaminator comes from the enviroment the engine lives in...my personal opinion, comparing our propane powered equipment vs. gas and deisel equipment, is that the fuel along with the combustion process causes more crankase contamination.

If the oil is contaminated more with air ingested to the engine, then changing the airfilter along with the oil/filter would be the best...but is it really necessay? I don't recall the suggested airfilter change recommendation, but isn't something like 15K or 1 year (for most GM vehicles)?

Thanks.

 

Mike,

While this is "technical", it isn't completely "auto tech", so it may get locked.

This particular example I cited was on two Quincy QS1000 screws and one Sullair 200/1000 screw. We were able to increase the interval from 1,000 hours to 2,500 hours. While this seems contrary to what I may have said in the past about increasing the change intervals for auto engines, there are some significant differences:

1. The typical sump size was 70 gallons, not five quarts. Contaminants were dispersed over a larger volume and therefore not as concentrated in the oil. Allowable PPM for particulates would take longer to achieve the threshold point for changing by the sheer volume of oil (just like in a large truck engine/sump);

2. There was full-flow filtration for the oil, and the filters STILL got changed at around 800-1,000 hours (just like in a large truck engine/sump);

3. At the same time, samples were taken at the filter change intereval for analysis. Monitoring oil condition was key in being able to determine the effective life of the synthetic;

4. The compressors were commonly operated 24 hours a day for five days straight. This helped maintain oil temperature and prevented moisture contamination and acid formation (just like in a large truck engine/sump);

5. The compressors had huge air inlet filters that were oil-wetted to clean as much atmospheric dust as possible from the air (more on that later);

6. There was a large oil/air separator that helped filter the oil even more by trapping the larger particles before they exited the compressor and got returned to the sump.

Through judicious management of the lubrication on these compressors, the air-end (actual screw section) was able to maintain adequate output efficiency with more than 60,000 hours of operation logged. (To my knowledge, they may still be running.) Others who were operating the same units had to replace worn out air-ends routinely at 20,000-25,000 hour intervals due to wear and poor rotor sealing. The extra expense of the syntheitcs was more than justified in saved capital repairs, downtime, and labor. This isn't even considering the environmental benefits of not generating three times as much waste oil.

As for the reasons larger trucks can run much longer on an oil change, some of the same reasons apply. They typically stay running and at operating temperature longer. You don't fire up the old Cat 3508 to run the grocery store then shut it off. This significantly helps reduce moisture contamination and acid formation.

Another major reason is that most larger trucks have massive air cleaner assemblies, many of which are oil bath types. These filter the intake air much more effectively, keeping atmospheric dust out of the engine (and oil). Most of the sludge and actual particulate comtamination created in a properly tuned and running engine can be traced to atmopheric dust, while only a very small percentage is due to the combustion process. Some of the chemical and molecular changes of the oil are due to combustion and heat, but the true contamination is mostly atmospheric.

So regardless of the type of lubricant used in an engine, the contamination still occurs. Thus the need to maintain a regular change interval. If you operate your engines more like an over-the-road truck than the typical commuter vehicle, you can safely extend the change interval. Then again, if you maintain your vehicle like an over-the-road truck, you'll keep a lot cleaner air filter in place as well. You might even have a dual full-flow filter array that stages the filtration (some people have actually done that on private and fleet vehicles).

This is not any great secret - even your owners manual acknowledges this and has two different service schedules for the differences in driving habits. The difficulty most of us have with that is most of us wouldn't categorize our type of driving as "severe", when in fact it is by their definitions. Instead of the terms "severe" and "normal", car manufacturers should change the designations to "normal" and "extended", or something like that.

Then again, a lot of people will religiously put 5W-whatever oil in their engines just because the filler cap says to do that, and never read the owners manual to understand why that may not be the best idea. How do you fight that kind of logic?

I do my maintenance based on results, experience, and science, not guesses, gut feelings, and promises.

I realize that propane fueled engines run a lot cooler, and a lot cleaner than a gasoline engine. While there is less chemical contamination of the oil from combustion, atmospheric contamination still occurs. If you sample the drained oil, you can perform both a chemical analysis and particulate count to determine the likely sources of contamination. Many places offer the chemical (spectrographic) analysis, but try to find someone with a particle counter. I used a Parker IQS-2000 to derive particle counts down to 0.5µm. This will give you a better idea of source when used in conjunction with the spectrographic analysis. The counts of larger particle sizes, instead of just the percentage or PPM will help you determine how much is internally generated from combustion and how much is injested from the air. If you look at 15+µm particulates in your propane engines versus the same counts in a gasoline engine, you might be surprised at how close they really are. Dust is usually large compared to the particles precipitated out by the combustion process. The PPM or percentages will likely be a lot lower on the propane engine due to the cleaner combustion, but the counts of larger particles (the ones that are most abrasive in a mechanical assembly) are probably very close.

 

Thanks for the the time to reply.

Is it safe to say then, that oil discoloration does not necessarily mean the oil has "mechanical wearing" particulates. I realize only a sampling/testing of the oil could confirm or deny this. As far as the discoloration (darkening) of oil, that would be more of the oils loss of lubricity?

See, what I'm driving at here, is our propane engines run in the same enviroment as our gas and diesel engine lift do (tractors don't count, they're in the fields) and the propane lifts' oil looks as clean (non-discolored) as the day it's poured in, while after about 75-100 hours on the gas lifts, the oil looks like it's been in a car for 2500 miles...diesels another story, I think the high compression blows the diesel past the rings anyways.

I'm wondering if were "reading" the oil wrong...we usually change the oils in the gas rigs at 100 hours, run the propanes out to 500 hours.

I guess an oil analysis would be the tell-all, we've talked about it, just never got around to it.

Do oil analysis's give feedback on lubricity, as well as particulates?

Oh, and yes..I think this is Tech related and fit's very well into the topic forum.

 

Don't really know if this applies to what you guys are talking about, but the Army uses oil analysis exclusively. They won't change the oil for any reason unless the sample comes back bad. Granted many of their vehicles don't run alot of miles but I've seen diesels go 3 or 4 years without a change. That's with a huge amount of idle time and such, mostly the lift/ recovery vehicles.

 

there is nothing like this topic to stir up conversation. you should hear the discussion when this applies to motorcycles. it get's downright UGLY. synthetic vs. dead dino juice is always a lively topic. in reality one can change the filter every other oil change and probably never have a problem. certain conditions such as an extremely dusty environment can change requirements. for the price of a filter the answer is a given. vader explains most of what I have learned in the last 10 years or so about oil and the benefits of synthetic. I guess if you want to look at this subject realistically as opposed to our love of our cars it kind of goes like this. at a 3k oil change schedule you can in all reality skip the filter and go to an every other. my maint. schedule for one of my new Honda sportbikes says this- after break-in 8k for oil change and filter every other. this schedule maintains warranty status, and they are requireing only the use of mineral based oils. this engine in question is a 996cc. V-twin, liquid cooled 108 hp. motor with redline around 10 grand. also in a bike the oil is used for the trans. lube and is subject to more shearing stress than is present in our auto engines. another thing to keep in mind is that oil filters are running in the bypass mode a lot of the time. an AC filter bypasses at around 11-17 lbs. and when in bypass the filter is basically non existent. for environmental reasons there is a movement afoot to lenthen oil change intervals and I have even heard talk in some areas of banning at home oil changes. if you run mineral oil look for a high flash point, this is an indicator of a good base stock and use an OE quality filter. I run synthetic and use the AC UPF-25 synthetic media filter. what is really needed and what we motorheads do are two radically different things.