"A 3000 mile interval is generally best" - fact?

[Threxx]

There's a know-it-all car guy on another forum I'm on... I've called him out countless times on touting his opinion as fact in the past on subjects that I'm familiar enough with to discuss intelligibly.

But in this case this guy is talking about oil change intervals and saying things that don't match at all what I've generally heard from those who know what they're talking about.

I'll just quote exactly what he's said...:

(this is his response when somebody said that the 3000 mile intervals were created by the quick lube shops to generate more revenue)

Quote:

---

It is NOT a ploy of quick-lube shops....that is a myth. Even Consumer Reports, so well-versed on most auto issues, has let themselves be duped to some extent with this. 5000 miles, regardless of what is in the Owners' Manual, is OK of you are driving long distances, at moderate temperatures, on uncongested roads, with little traffic, or using synthctic oil, but it is clearly TOO LONG when you deal with the conditions many of us do today with endless stop-and-go traffic, regular petroleum oil, and short trips. 3 months/ 3000 miles is best under those conditions....you can go to maybe 4 months if you don't have the 3000 miles yet after 3 months.

My oil gets changed every 3-4 months with a factory filter and Castrol dino oil...either by myself in the driveway or in the dealer service bay, depending if I have the time...and I have never had any engine oil-related problems.

---

(now he continues when he was told that a 3000 mile oil change may be 'safe' but was not factually 'necessary' to prevent excessive wear)

Quote:

---

even if the oil itself does not suffer viscosity breakdown ( as dino oil does at high temperatures ) the additives and detergents wear out. Those oil additives perform a number of important functions besides just general oil lubrication and heat absorbtion.......cleansing of deposits, anti-scuff action, evaporation of moisture, suspension of engine-metal-wear shave particles, etc......
But....for MOST of the type of driving we do today in urban and suburban areas, 3 months / 3000 miles is generally best. That is a fact, not an opinion. Today's endless stop-and-go driving is murder on engine oil, even with the good quality oil we have today ( SM grade, now ). And in fact, many automakers agree. For " severe service " intervals, which is what most of us actually encounter today, they recommend about half of the standard 7500 mile interval......3000-4000 miles, which is pretty much what I said.
Several automakers have tried out on-board computers that " monitor " oil condition based on number of cold starts, short trips, starts/stops, engine load, etc.....and signal for an oil change after a certain number of them, but experience with these devices has shown that the engines don't stay as clean as they do with standard 3/3000 changes. BMW, for example, has had more warranty work and engine replacements with these oil monitor devices than they did the old-fashioned way with regular oil changes every few months.

So......CAN you stretch oil changes? Sure you can. Will the engine suffer? In many, if not most, cases, yes. And some engines simply will not put up with it.....they will bite you......as the topic of this whole thread to start with....the Toyota / Lexus 3.0L V6.

---

Now of course I understand certain engines you'd rather be safe than sorry - such as the Toyota 3.0/3.3... but that's the exception, not the norm.

So what is your guy's take on this? I'm not asking you to agree with me or agree with him - I'm asking for your honest opinion, if not some oil tests to back your opinion up demonstrating under what conditions a 3000 mile oil change would go from "well, if it makes you feel better" to "that's probably a good idea"?

 

[williar]

I'd look at what the better automotive oil life monitors do. They account for a variety of factors, only one of which is mileage.

 

[javacontour]

Frankly, what he is saying probably does no harm.

If the average soccer mom, who never raises the hood of the minivan when getting gas followed his rule, then she and her vehicle will probably be fine.

What most folks miss is the time component of an OCI. Even you missed it in the title, you only addressed the mileage.

I agree that many folks, maybe even most folks DO drive in the severe category.

So, maybe some folks can go 5K or 6 months between changes with conventional oils. But if they don't check the level, it might be two quarts low at the end of the OCI.

For us obsessive compulsive types, who check the oil at least weekly and perhaps at every fuel stop, we can probably go 7K + on regular oil, if we are doing that in say three months of driving.

If you are going to follow ONE simple rule, then 3mo/3K miles is probably a pretty good one for the average Joe/Jane who doesn't give a rip about cars other than does it have gas to get me where I'm going.

 

[Gene K]

If you are using up SE oil from the early 1970's in a 1973 455 then yes.

If you are using Modern Group II SM/GF-4 conventional in a modern engine then 5000 - 10000 mi OCI depending on model is fine.

You might want to ask him how IL State Police were able to run their LT1 Caprices with only 5 Qt oil capacity 200,000+ mi including extended idling and pursuit work with 15,000 mi OCI (using synthetic).

I would ask him to give the SAE research and oil analysis to back up his opinion.

Ohhh, while you are at it you might ask how a CAT3406E powered truck can last 1.5 million miles on conventional oil changed every 30,000 mi.

Might also want to ask him about the SAE research papers which shows most engine wear occurs when fresh oil is in the engine. How is increasing engine wear with an excessive number of oil changes going to help the engine last longer?

 

[Threxx]

Quote:

---

Frankly, what he is saying probably does no harm.

---

Yes, I definitely agree with that, however I'm trying to seperate 'if you don't do this you WILL cause excessive wear to your engine' from 'does not hurt anything and adds a little peace of mind'

Quote:

---

What most folks miss is the time component of an OCI. Even you missed it in the title, you only addressed the mileage.

---

If you only knew the number of times I tried to word that title to get the point of the subject across and kept hitting the relatively low (for a web forum) character limitation... I was getting frustrated.

 

[Gene K]

Well there is a over one year 18,700 mi OCI on factory fill in Porsche Boxster on this site and the
Used Oil Analysis looked just fine. Especially when you consider the break-in wear represented.

 

[michaelc80]

Quote:

---

Several automakers have tried out on-board computers that " monitor " oil condition based on number of cold starts, short trips, starts/stops, engine load, etc.....and signal for an oil change after a certain number of them, but experience with these devices has shown that the engines don't stay as clean as they do with standard 3/3000 changes.

---

Rather than make statements it would be nice if he were able to provide links to documents that back up what he says. Perhaps some tests that back up his assertions.

 

[benjamming]

Who does he work for? JL?

 

[Mystic]

I personally like to go by what the manufacturer of the vehicle says. I drive a Saturn Ion. It says in my owner's manual that the oil should be changed every 3000 miles/3 months in SEVERE driving. If you look at what is defined as severe driving pretty much everybody is in that area. In addition Saturns in the past at least had a metal chain timing belt and the story was that the oil definitely should be changed every 3000 miles. I don't know if that applies to Saturns with the new engine. I figure that the people at Saturn Corporation probably know at least a little about car maintenance. So I like to change my oil every 3000 miles/ 3 months. I use conventional oil except in the wintertime when I think a synthetic is better because of the cold. I also use Auto-RX in maintenance doses and also do an Auto-RX cleaning every 25,000 miles.

People can argue all they want about how (with some motor oils) you can and should drive 15,000-25,000-35,000 miles (there is usually a qualifier in there somewhere to still change once a year). If I tried to drive 35,000 miles on one oil change I would be changing the oil every 2 years.

It can't hurt to change the oil every 3000 miles/3 months. You can go to Wal-Mart and buy a 5 quart container of Valvoline oil for about 10 bucks. This is high? How much does your auto insurance cost every year? Sometimes motor oil can be found on sale for less than a dollar a quart. Even at 2 bucks a quart 5 quarts is 10 bucks, a few bucks for an oil filter, and if you have your own ramps and do the job yourself you are probably talking something like 60 bucks a year for 4 oil changes on one vehicle. This is a lot? How much did the car/truck/van/SUV cost?

Now motor oil for a Corvette is going to be more expensive. You need to use Mobil 1 or a comparable synthetic. But somebody driving a Corvette can afford more also than somebody driving a Camry. With the Corvette and the synthetic oil maybe 6000 miles/6 months would be better. What does it say in the owner's manual for a Corvette?

So now let us bring up waste oil. Some say-'You are wasting the Earth's resources, polluting the environment, if you used synthetic and went 35,000 miles between changes you would be using less oil,....' Well, I don't pour the used oil into a river or a lake. I recycle the used oil. I take it back and pour it into used oil waste containers at the auto parts stores. It gets recycled. Surprise! I do care about the environment!

 

[Patman]

Quote:

---

Now motor oil for a Corvette is going to be more expensive. You need to use Mobil 1 or a comparable synthetic. But somebody driving a Corvette can afford more also than somebody driving a Camry. With the Corvette and the synthetic oil maybe 6000 miles/6 months would be better. What does it say in the owner's manual for a Corvette?

---

It says to follow the oil life monitor, or one year. On the 97-00s, the oil life monitor was calibrated based on a 10,000 mile maximum, so it counts down faster than the 01-07 models, which are based on a 15,000 mile maximum. My 98 typically hits 0% oil life right before 7000 miles (last time it hit zero at 6850 miles) If I owned a newer one with the OLM calibrated for 15k, that would've translated to 10,275 miles before the OLM hit zero.

 

[427Z06]

javacontour summed up my thoughts for the most part. If I were to make a blanket recommendations I'd just tell people to look in their owner's manual for the severe service schedule and use it. For a 2004 Honda Civic, it's 5,000 miles or 6 months whichever occurs first. For a 2002 Honda Accord V6, it's 3,750 miles of 6 months whichever occurs first. Quite a bit different than 3,000 miles or 3 months.

With OLMs, you take all the guesswork out of it. I have yet to see any credible evidence that OLMs aren't working as intended. My only complaint would be those implementations that just incorporate an idiot light.

Further, look at the EOM test someone recently posted. They used cheapo dino in what was obviously severe service. Even with 15,000 mile OCIs for cars that have a 7500 mile OCI under NORMAL service, they were still running fine after well over 100,000 miles. Sure some of them were sludged up a bit, but that was under what was probably four times the recommended OCI.

One last point. I wonder how many have considered the fact that the allowable amount of sulphur in gasoline has dropped substantially in recent times.

 

[Mystic]

Based on this I would assume that any car/truck/van/SUV of recent vintage and with a good engine and not operating in some extreme situation like racing or severe dusty conditions could probably go 10,000 miles/1 year with Mobil 1 (or a comparable synthetic).

I am pretty paranoid when it comes to oil changes and if I owned a Corvette I think I would still change the Mobil 1 every 6000 miles/1 year or twice a year.

Every mechanic I have ever know (and I have known quite a few) was compulsive/accessive about oil changes. The most any of them would say was that you could drive a few hundred miles past 3000 and you would be okay. Some of them believed in urban legends (like Pennzoil causes sludge) but all of them, no matter what brand of oil they used, changed their oil on a regular basis (typically every 3 months/3000 miles).

I think I would go flat out crazy if I tried to drive my car 15,000 miles on one oil change (using Mobil 1). A person probably can do it but at least you want to check the oil and be sure it is not low, if it is low add oil, and maybe change the oil filter and add some oil at 7,500 miles.

Now, those big highway trucks probably often go 15,000 miles on one oil change, or even more. But they have super filtering (oil & air), are driven almost exclusively on the highways, and they have a LOT of oil. A car or truck properly modified could do the same-higher capacity oil pan, bypass oil filters, a very high quality air filtration system, etc.

What is called SEVERE system in the manual is actually NORMAL service. There are probably only two kinds of guys who drive in the so called normal service. The travelling salesman who always drives on the highway and puts a lot of miles on in a clean environment, with normal temperatures and no towing, and the guy who drives cars and trucks in testing labs where the vehicle is run on rollers and the air is clean and temperatures controlled. Those guys are okay with 7,500 mile conventional oil changes. And those gusy could easily go 15,000 miles using Mobil 1, keeping an eye on oil level (or having a lab assistant keep an eye on oil level), and maybe changing the oil filter twice as often as the oil and adding some oil along with the filter change.

 

[greaseball]

I was always an advocate of a 2000 OCI-eeek-but the forumites here wanted to kill me!!! I have now moved to the 3000 OCI criteria. I did notice that when I started going to the longer OCI, I had to add oil to my 145K Intrepid. So 3K is my max.

 

[Vilan]

Point him to the UOA section here. No opinions there, just hard numbers. Plenty of people who've modestly extended their OCI with no visible harm done.

 

[Mystic]

Those people who want to go 15,000 miles or one year using Mobil 1 or a comparable synthetic should remember a few things.

For one thing, it probably says on that container of Mobil 1 or Redline or Royal Purple or Amsoil that the oil should be changed every year even if you don't reach the 35,000 miles. So if you only drive 15,000 miles in one year that does not necessarily mean you can keep driving until you reach 35,000 miles.

You also need to keep into consideration what kind of environment you are operating a vehicle in. Do you drive your car or truck in an environment where there is a great deal of dust? Are you racing your car?

Now, going 15,000 miles or one year using Mobil 1 is probably just fine (depending on what it says in your owner's manual). But going that far on an oil change you probably need to check oil level frequently. 3 quarts of Mobil 1 in a vehicle that uses 5 quarts of oil is not good. Even using Mobil 1. So keep the oil level topped up. And if it was me I would change the oil filter at 7,500 miles and add some oil to make up for the oil that was lost in the oil filter.

Now the mechanics at this site can explain where I am going wrong.

 

[Gary Allan]

I'll go with javacontour and 427Z06. As a blanket recommendation ..without any qualifications (the rise or fall of the yen - long term migratory trends of slugs, etc.) you can be assured that you will compensate for any smack-arse behavior by just about any consumer. One thing, that I didn't see mentioned, is that most cars will not consume any oil over a 3k/3m span. This would take a good bit of negligence out of the numb owner equation. OLM, without a low level warning system included in the package, cannot compensate for that consumer defect.


In the absence of OLM, I'm sure that any manufacturer's recommendation has some mean or median ..where there is a surely some fudge factor ..factored in. That is, @7500 ..surely there will be so many that could have gone 9k ..and a few that should have gone 6.5k. This is probably not quite as true for the lower recommendation ..at least on the lower end of things. 3k/3m should totally include any number of variables to the point that any more maintenance would be more expensive than the liabilities.


As far as taxi service goes, it's obviously not all that severe. At least in a conventional sense. No taxi gets serviced every 3k ..that's way too much downtime and costs more in lost revenue. That is, it would be cheaper to put in a new engine with all the hours that the thing would be in the shop. We've seen many that get 5-6k OCI's go 300-400k without lubrication related problems.

So we can say that 3k isn't a mandate ..or that taxi service isn't as severe as we tend to regard it. I think taxi service isn't all that stressful. The problem is that it's very hard to figure "true" mileage when most engine use should be measured in terms of fuel consumption. Obviously ..the 5k-6k OCIs that result in 300-400k life cycles are some result of the proper fuel consumption profile for a very long life. That is, it may have worked out to 10k for a 100 mpd commuter that didn't spend that much time sitting idle.

 

[jmac]

Iam definately a longer OCI advocate, but under certain conditions especially with bulk oil I would say that 3mos/3000mi interval certainly has justification especially with an engine that may have been neglected a little in the past. Percisely those conditions that he outlined on basic, "who knows what is in there" type oil . Since this is a safe overall minimum this is what is touted as the norm for the Universal OCI regardless of oil in use and driving condition for the majority of people that have no wish to think more than two nanoseconds about the oil in their car.

 

[Mystic]

They like to use taxicabs in these test for some reason. Probably the average person thinks a taxicab has a hard life. But actually the most severe type of service possible is probably the person who drives their car only a few miles and the engine never really reaches operating temperaure. That person could WALK to work!

If you drive your car or truck only a few miles, especially in cold weather, you better at least take the car for a highway drive on your days off from work. And maybe consider riding a bicycle to and from work on nice days and leaving the car or truck at home. A car or truck has to be driven long enough so that various stuff produced during engine operation is boiled off. Gasoline engine combustion produces by products that are not good in the engine, like various chemical combustion products and water. If that stuff is not boiled off it will build up in engine oil and comtaminate the oil. You will not be able to easily tell if you have enough oil in your engine-the level could be off because of all the contaminates. And the contaminates cause engine corrosion and lessen the ability of the oil to lubricate.

The most severe service there is (except maybe very extreme dusty conditions) is driving a car or truck only a few miles at a time, especially in cold weather, where the engine never reaches operating temperatures. If it is that close to work maybe get a bicycle.

 

[Patman]

I personally think that 5000 miles is "the new 3000 miles".

If you want to cover all the bases, you could probably suggest to someone that 5k or one year is what they should follow. And in 99% of the cases, that engine will last longer than they want to keep that car anyhow.

Oils are better, fuel is cleaner, engines are better (much less fuel dilution now than with carbs!), but yet people still cling to the 3k interval like they did 20 years ago.

 

[Mystic]

You probably know somebody like that. There is a guy I know where I work who lives only a few blocks from work. He works Monday-Friday with weekends off. He does not have to work nights and risk getting mugged. In good weather he could easily WALK to work. But every day he gets in his vehicle and drives to work. I would not buy a used car/truck from him.