Stop Changing Your Oil

wc19805

After running 9,000 miles on synthetic oil in my 17 rear old car theres alot of variables that nobody seems to understand. My car is fine but even with a properly working emissions system the oil still came out thick & lumpy & extremely nasty. I can only imagine what the oil would look like if I had left it in all year. I did use 2 filters & changed them out mid oil change. Guess I know why they have a "bypass" in the filters in case they clog. Anybody that has an investment to protect will stay aroud 5,000~7500 miles max on an oil change. Yes we (the dumb consumer) know you technically can go for 15K but its plenty dirty at 7500mi.

drexellake

7000-10,000 miles is common for oil changes now days. BMW recommends synthetic changes at 10-15k mikes. Granted I would not try this amount of miles with a cheap or reman oil. Mobile 1 guarantees 15K miles for their oil. Most people do not in fact drive under extreme conditions unless you're ice trucking north of Canada or commuting through the Mojave Desert.

ziggyff

You can easily and safely go 10k - 15k miles if you use synthetics..I've been using mostly Mobil 1 and Pennzoil Platinum for 30 years with a 12k-15k oil change cycle, never have dumped a car because of engine trouble since, usually suspension repair expenses or rust have sent them to the junkyard. That includes multiple Subaru 4 cyl, VW diesels and Toyota and GM trucks 6 cyl.

sideview65

This article is so full of myths of its own, that I hardly know where to begin. The idea that the fast oil change industry is the only one recommending the 3000 mile interval is bizarre. So is the assertion that oil technology has changed radically in the last 20 years. Modern motor oil is a complex mix of base stocks, detergents, dispersants, and long chain polymers. But over the 3000 mile interval, those ingredients break down or become contaminated, and as they do, your oil is no longer able to maintain its integrity. Those long chain polymers which make a 10w-30 do its job in summer heat and winter chill, break down. The oil's ability to clean, lubricate, and hold contaminants in suspension, is degraded. And over time, both the oil and the filter become increasingly fouled with the byproducts of combustion.
How many times I've read that tired old saw: today's engines have much tighter tolerances than they did 20 years ago. Well, if you go to your auto parts store, and pick up a few Haynes manuals, and compare engine tolerances, the truth will set you free. A 1967 VW bug, for example, has bearing clearances every bit as tight as many modern engines. Tighter tolerances are not a reason to extend oil change intervals, either. Quite the opposite. Squeezing old, contaminated oil through a close tolerance surface is likely to be more, not less, damaging to those bearing and journal surfaces.
Manufacturers of automobiles have a vested interest in recommending long change intervals. They want you to wear out that car you're driving, and go to the dealer for a new one.
A 10,000 mile change interval only makes sense if you are indifferent to your car's longevity. Synthetic oil won't help you out, either. It gets contaminated, too, and when it does, all you're doing is pumping those contaminants around your engine. over and over again, in an expensive carrier fluid. Most people change the filter only when the oil is changed, and anybody who thinks an oil filter will still do its job at 10,000 miles is out of touch with reality.
Changing the oil and filter at the 3000 mile interval is the cheapest, best insurance there is for protecting the second most expensive investment you own. The quick oil change industry's motives may be suspect, but they aren't the only ones with ulterior motives. Let the buyer (and the reader) beware of wolves in sheep's clothing.

300thousand

2002 Chryser town and country with 285,000 highway miles and changed the oil at 25,000 miles or more. Still not using any oil and drive only a few miles aday now as I am retired..............will change oil about every 10,000 miles or maybe once a year. The service industry has everyone giving them money.

boiner53

The thermal breakdown of oil will only happen if you strike a match and burn it. Oil will burn. The problem with oil in any application is that it gets dirty. Clean the oil and it will keep lubing forever unless "see above". The oil filters in the automotive industry just don't clean that good. It has to do with money. (Small micron) filters such as the ones used in the aircraft industry are very expensive. How do you think they recycle oil? It is filtered, not magically reformed or reconstructed into new oil. Recycled oil never is as clean looking as new oil because the filters they use don't filter all if the carbon(black) out. To get there, (no black), is cost prohibitive. I knew an instructor at an aircraft school that drove an old Chevy 200,000 miles without an oil change. He changed the filter at regular intervals and added oil as needed. It's not the oil, its the filter. Keep it clean.

osmfac

Worst advice ever! I am the unfortunate owner of a Dodge with a 2.7L engine. I never went over 5000 miles without changing my oil, and I always used synthetic oil. At just under 100k miles my engine blew- due to sludge in the engine. The original engine only had a 60000 mile warranty so those every 3000 mile oil changes likely would not have helped me. However, I have an OEM replacement with a 100k warranty and I was warned repeatedly that without the proof of every 3000 mile oil changes that warranty will be void. My owners manual says differently, but Dodge will not back their product without proof of oil changes every 3000 miles- one glance at the dodge forums will verify this... is $1800 over the LIFE of your vehicle worth an out of pocket engine replacement? Not to me.

rwthomas1

Engine oil monitors are great BUT there are still concerns. You are trusting the monitors to do their job. I have a tough time believing that the manufacturers really care how well these work. Even with 8K-10K changes, most any car will go 100K, which is longer than most keep them. But how do you really know the oil change is appropriate? You don't, unless you analyze the oil. That is not what most car owners will do. A 6K interval is probably a reasonable compromise. I know I use a 8K interval on the gassers and 5K on the diesel but that is confirmed with oil analysis and synthetics. I can't imagine what would happen if someone arbitrarily chose say a 12K interval without doing a little research. I know there were several engines in the last few years that would "sludge" up after 4-5K. Kinda important to know about that....

retiredcarl

In PA Hyundai Dealers Claim All Owners Are In "Severe Usage" Category. ( One Even Told Me Every Car In The US Falls Into This Category, Won't Say What I Told Him! :-) So Oil & Filter Must Be Changed Every 3500 Miles Or Owner Voids Warranty. Plus All Fluids, Transmission, All Wheel Drive, Radiator, etc, etc Must Be Every Changed Every 30,000 miles. No Wonder They Can Afford To Have Such Long Warranties Since The Cost Of Required Maintenance Covers The Small Percentage Of Warranty Repairs They Will Incur.

prometheus5

BMWs actually monitor your oil quality and will tell you when its time for a change. My last oil change lasted 20,000 miles before my car told me it was time for service, and the dealer said the oil actually looked good and probably could have gone another 2k miles. So, 22k miles....versus 3k.

finalechelon

Sorry but every, and I mean *every*, engine is different. So unless you're performing UOA (Used Oil Analysis) at least every oil change then it's all just speculation with a side of educated guess-work at best.

Given, if your vehicle is new, under warranty and you don't expect to keep it once the warranty expires then by all means change the oil at or before manufacturer recommended mileage because if you have a failure then it's on their dime.

But if you really want to extend the life of your engine (in-warranty or not, but especially if not) , then spend an extra $25 each oil change, get a UOA and adjust your change interval and/or oil choice accordingly.

"But I don't want to spend $25 more! That's a lot of money!"
No, an extra $25 every 3+ months or 3,000+ miles is *not* that expensive. Especially when compared to the cost of unexpected engine repairs and the fact that engine failure never happens at a place and/or time that is convenient.

Don't change your own oil?
Ask whoever changes it to save an ounce or two of the old oil for you. If they refuse, take that as a red flag you need to find some place new because they're probably short-changing you somewhere.

Don't know how to read a UOA?
Go to http://www.bobistheoilguy.com to meet helpful people and learn something new. It's good for you.

FE

"In the long run, education and exercise will solve most of your problems. Try it."

makinchips

I'd like to see more about spark plugs and oxygen sensors, spark plugs from the factory can last 100K+ miles and our well meaning quick service buddies will try to change them at 30K using an inferior
(non iridium) replacement.

on the other hand, unless you have an engine light on, nobody thinks to swap out that oxygen sensor that's been running in corn fumes for 130K miles and is now reading out of range, these sensors single handedly have the greatest effect on fuel economy because they directly conlrol the fuel mixture.

cunconli

I changed synthetic oil on my car between 10,000 and 15,000 miles and it is close to 150,000 miles now still running great. So I concur this article that 3000-oil change is a waste. I had my 2001 Honda Accord before with non-synthetic oil changed every 5000 miles and was absolutely fine until I crashed it in an accident at 101,000 miles.

q185225

Did you brainiacs ever think about the filter? It clogs after about 3,000 miles. I am judging this on my 40 years of working on cars & trucks

pappaapsu

This article is a good way to get sued. I have a 1990 Toyota Corolla. If I did an oil change after 7,500 miles, my engine has a good chance of seizing. I follow the recommendation in the owner's manual. That would be my suggestion. Read your manual, perform it's recommended services. If it says to change the oil every 3,000 miles, DO IT! The book came with the car for a reason. I have over 200,000 miles and going strong. If you have an older car, disregard this article. It will do more harm than good. It may even destroy your engine. If it is a newer car, by all means, if the manual agrees with this article, do it. Todays "synthetic" oils are definitely more complex, and allow for longer intervals between fluid changes. I used to work at Valvoline. (Jiffy Lube is not the best of role models when it comes to reputable companies.) I don't play the Valvoline is better because I worked there game. Valvoline IS better. Look up Jiffy Lube and 20/20. They lied in over 20 stores across the nation about their "better" oils. It was really basic oil in an upgraded oil container. Shameful. Anyway, read your manual, that is why it is there. If you don't follow it, you may void your warranty. To think, the government actually uses Edmunds to validate the car values for personal property tax. Horrible.

mungofatkid

It's not the oil that is the problem. It is the oil filters. I've seen these filters disintegrate after 3,000 miles. Nothing like running non-filtered oil and parts of the filter thru your very expensive engine just to save a couple of bucks. Have fun with that. I know I will have fun replacing that engine. Happens all the time...

knower

The 3,000 mile standard is a very old "recommendation" and is now basically a scam. My 96 Accord stated right under the hood to change the oil every 7,500 miles. My 2001 Civic states 10,000. Do you think that Honda wants to be known for having engines that fail at 100,000. They pride themselves with 300,000+ mile engines. they would never recommend something that would damage this reputation.

windsailor

I have a 2010 Porsche and use common sense to protect the engines innards. I started with a 6,000 mile oil change and sent a specimen for oil analysis. The analysis showed that significantly more mileage could be accommodated. So I went to 8,000 miles for the next one and that showed that yet another 2,000 miles could be realistically added.

I have to agree with this article, too much snake oil advice is being doled out. A simple oil evaluation for your particular car and use will answer your change interval better than all the gurus in auto shops. Blackstone Labs is one, but more can be found by a google search.

windsailor

I have a 2010 Porsche and use common sense to protect the engines innards. I started with a 6,000 mile oil change and sent a specimen for oil analysis. The analysis showed that significantly more mileage could be accommodated. So I went to 8,000 miles for the next one and that showed that yet another 2,000 miles could be realistically added.

I have to agree with this article, too much snake oil advice is being doled out. A simple oil evaluation for your particular car and use will answer your change interval better than all the gurus in auto shops. Blackstone Labs is one, but more can be found by a google search.

sonny53

I have always said that if you are not police , fire , ambulance , taxi , or someone who sits with the engine idling for long periods then you are throwing your money away and wasting oil using the 3000 mile rule ! I am a factory trained, master certified mechanic since 1976 . The 3000 mile rule is to sell parts and service .

takespix

I own a 99 Jeep Wrangler with 285,000 tough miles in the Appalachian Mountains. The engine is the original and other than a valve cover and oil pan gasket, has never leaked or failed. The oil gets changed every three months or 3000 miles,which ever comes first. It used non synthetic 10w30 oil.
I also own a 2012 Hyundai Accent that came factory with 0w20 full synthetic in the crankcase. The owners manual says 8,000 mile maximum intervals between oil changes. Because I drive all highway through a mountainous region I change it around 6,000.
I work in an auto center and I get to see first hand how oil can sludge from going too long between service.
The new cars today CAN go farther because in most cases are fully synthetic. (E.G. GM "dexos") Depending on your driving, you can go 5, 6, up to 8K mile intervals.
It all boils down to what you're driving, how you're driving, where you're driving and the age of what you're driving.
It would be foolish to the owner to make an across the board assumption that money is wasted on frequent oil changes, especially if you don't plan on trading your vehicle in less than 150,000 miles.

ctblizzard

I understand the point, but I do think the author is missing something. Checking the oil occurs in a process in which other fluids are checked and a maintenance schedule is reviewed, tires can be rotated etc. The visit is not just about the oil. Having someone review the oil, know if you have a problem, have a fluid which is unusually low, get basic things done like wiper replacements, bulb checks etc goes a long way to getting peace of mind regarding the basics.

ronhudson

I have a new chevy and their requirement is to use their dexos oil and follow the oil monitoring information. Unfortunately, there is a second part to this equation and that is the quality of the oil filter.I'm not an expert on oil filters, but I do know that the quality does vary considerably between brands.Unfortunately, the layman has very little information on this but generally speaking one should avoid one brand like the plaque

vic39

I have a 2011 Jeep Wrangler, and even though the OEM recommendation on the User's Manual is 6,000 miles and it has an Oil Monitoring System that turn On a Change Oil message around the 6,000 miles. I keep getting calls from the dealership reminding to take the vehicle to their facilities to change the oil.

ttigger06

Ok, so they're talking about current and new cars. I have a 96 Silverado. She's had her oil changed every 3000 miles over the last 8 years that I've had her. Not a single engine problem. I say when some of these newer vehicles reach 265,000 HARD driving miles and is still going, then I'll consider extending the miles between oil changes. In the mean time I'm fixing to hand my keys to my now 16 y/o for him to finish high school out with it and not have car payments. I'm getting me a new vehicle, but I'll STILL chage the oil at 3000 miles. I guess another way to look at it is their difference in expenses over the life of the vehicle is less that $2k. When that engine seizes up, how much will you spend in additional care payments? Thank you but no.

floyd17

Please, Please listen to this article. I love selling complete engines to people because they do not change their oil. If enough people follow this horrible advice I will be able to buy my new boat. I am going to name it Miss Diagnosis.

ritoco

As a Honda technician for more than 30 years, I have seen the advances in oil technology. Until Honda started following the "maintenance minder" system, the factory recommended service intervals were 7500 miles. Since the common thought was this is a little too long for oil changes, they were recommended every 3750 miles, not 3000. I've never worked anywhere that suggested 3000 mile intervals. 3750 mile oil changes also kept the 7500 mile service interval in sync, which was important, since this included tire rotation, which is extremely important for proper wear and longevity. Once the maintenance minded system was introduced, our oil stickers stopped giving a mileage interval, instead showing 15% or 1 year. This is the point that the dash indicator flashes for a few seconds after starting the car. Most customers came in between 5%- 10% left, which was usually between 6-8000 miles since the last oil change. For customers that just insisted on doing it by mileage we added 5000 to the currant mileage for the next change. The problem with extended oil changes is the lack of tire rotations, since tires need to be rotated more than every 12-16,000 miles. So now to make tires last the longest, they need to be rotated with every oil change to ensure proper wear. It can take some effort to get customers to understand the long term saving by adding extra cost in the short term.

david_b3

I asked my mechanic (who I trust 1000%) about this, and his opinion is to change at about 7,000. He sees (expensive) cars with recommended cycle of 15,000 come in with big glops of sludge in the oil pan. I prefer 5,000 because it's really easy to remember.

speedracer19

RRoeber and JimmJets33, you both missed the point (and the technology) in the article.

The oil monitoring systems on cars these days are not simply based on mileage driven, but HOW you drive your car (which can include the temps reached in the engine).

The faster you accelerate, higher speeds, etc, will affect WHEN YOU ARE TOLD it's time to change (and they'll play it safe somewhat). But 3K miles is ABSURD for any car today.

My car goes 10K to 11K between changes and still runs like new (13 years old now) - fast sports car, and I drive it hard and fast at times. Additionally, I have a 12 year old SUV, change oil every 12K miles...running well too.

neby

That's all very silly... I own a Honda accord v6 with 272k on it.... Guess how often I changed the oil? 5k every time, and I only buy the cheapest crap I can find after it hit the 200k mark. Now I'm thinking I'll go to 7k might as well. The transmission is going to give out long before the engine will, and probably at 350k the way it's running now.... But that's ok believe what your sold.

skipower2012

This is coming from someone who has torn apart thousands of engines and handles warrenty claims for a major automobile company. Just use your common sense here. If you drive your car for 20,000 miles with the same oil, we does all the dirt/debris from your engine go??? Even the best/hand build engines will have metal shavings or other things that can be hazardous for your engine. How do you clean that out, change your oil! I love the environment as much as the next person, but an engine block rusting in a junk yard and the energy put into building a replacement is more harmful to the environment than a couple quarts of oil. Plus, most of your oil is recycled or used to power the shops.

ridged8

One of the main purposes of oil is to hold the dirt inside your engine, in suspension. Which is one of the reasons it turns black. So, given that. I change my oil, when it turns black...when it's holding dirt. Irregardless of how many miles I have on it since the last oil change, because all miles are not created equal.
I drive a Dodge Durango, that pulls a trailer consistently. Loaded with granite counter tops, thus, lots of weight, stress. Up hills, down hills, etc.
I have over 375,000 miles on this car. I do the same wit the transmission. I had 226,000 miles on it, before it failed.
My record speaks for itself :-)

8aa2ym

Interesting. I think generalizations are OK in most cases. What it really boils down to, is caring for your car. I was witness to issues on turbo-charged Saab oil break-down created by faulty design. This problem was mitigated by swapping to synthetic oil and more frequent oil changes.

Bottom line. Know your car.

caarons

I strongly support the premise that 3000 mile oil changes are wasteful and un-ncecessary. I do oil analyses on my several vehicles.
For my $125K Unimog U500 chassis Mercedes recommends oil changes every 1200 hrs (it takes 30.6 qts of synthetic oil for a 6.37L diesel). That computes to every 42000 miles. The farthest I have actually gone was 21500 miles but the oil had a lot of life left in it.

Charlie

maddmac

I use mobile one extended performance. change the old every 15,000 or 1 year, which ever comes first. been doing it for years, 52000 on my nisson 78000 on my '04 hyundai xg350L

benztech1

The proper amount of time is around 5,000 miles if you want your risk factor to be in the 95% percentile. Beyond that it goesd to abnout 80% at 7500 miles. your choice. But, if you have an honest mechanic who is looking out for you then seeing him every 5k is to your advantage as they catch other small things before they become big things. if you are simply going to the dealer or jiffy lube type places then it doesn;t matter because they don't care about you by design.

The problem with synthetic oil is this... it breaks down the dirt into smaller particle, however great that sounds, those particles sneak past the filter and become one again on the other side causing sludge. Think about spraying muddy water through a screen onto a sheet and letting the sheet dry. You would see clumps of dirt on the sheet. This forms a grapgite kind of sludge in engines in all the nooks and crannies that are simply not there with frequent oil changes and non synthetic oil.

By the way... the elephant in the room that the press won't talk about because they don't want to lose advertising is how we are ALL being ripped off by high parts prices. why should a relay that runs the wipers cost 600 bucks whne an ipod is 250? Why should abrake caliper be 900 bucks when one another car that does the same function is 150? Why are headlight assemblies 1500 bucks and bumper trim piece 250 each? The integrated radio/gps "command" modules on audis and merceds are upawrads of 10k EACH and cannot be retrofitted because of the fiber opric communication protocols in the cars.

THAT is where the money is going.

Also... road salt is destroying brake lines, fittings and sensors for all of those required abs and traction control systems. and the bumper sensors for your bumper wanring system to "save" your bu,per are 200 bucks EACH and the car has 8 of them. Same foes for Tire proessure monitor systems. the sensors on most cars are 120 bucks each and they break when you change the tires if you look at them sideways.

Oil changes are the tip of a giant iceberg.

(google rusty brake lines chevy trucks)

cheapster505

we are used by everyone "Oil life 0%" makes my wife panic
thinks "NO OIL LEFT" in car She stopped at Jiffy Lube who put in two quarts" emergancy oil " I went back to that Jiffy lube and complained Got a 5$ off coupon guess I won on that time

mrsean7189

What about using the more expensive oils supposedly designed for high mileage cars?

taosjet

a big advantage to synthetics is that they don't wax or gel in winter weather so you get much better start up protection. this goes along with very good hi temp. performance that most people are aware of. I would change my mazda's oil once a year using full synthetic [about 15,000 miles] after 100,000 miles it burns no oil and has clean exhaust. I just gave it to my daughter and she is very pleased.

hane

I used to use what is commonly considered the cheaper oils as found in auto parts discount stores in the low cost section of thhe oil pile, when I drove my VW Dune buggy hard" after turning off the engine I noticed that my air and oil cooled engine would naturally bevery hot, but to my surprise I could literally hear it boiling in the engine. I pondered on the situation of having my lubricating oil at a full boil, and reasoned this just can’t be properly lubricating my engine, so to make this story short I switched to MOBIL ONE”, now that same engines oil does not boil, it is much quieter, and now I cannot smell the all too familiar smell of burnt oil. So there you go here is my plug for MOBLE 1. Shane

garykip

You can also have your oil tested at most of the larger CAT dealerships. I know they have a lab in Tukwila, WA and Cary NC. The cost is about $15. There is No OTHER WAY to know what is going on inside your engine, unless you take it apart or have x-ray vision.

wally40

When i used to change my own oil, at 3000 miles I could feel the dirt and grit when i rubbed my fingers together. I know the oil lasts, but I got to believe the grit acts like sand paper over time on the valves etc. That is why I change it.

nkfro

Ask yourself if you're ready to pay for engine repairs if the dealer rejects your warranty claim because you can't prove that you had the engine oil changed in accordance with the specifications in the owners manual.

gmorrison1

there is quite a large amount of unnecesry oil oil changes going on these days,look years ago when we had "dirty engines"it was a necessary thing that oil changes were done every 3-4000 miles,now since we lost this thing known as a fuel wasting carbeutor that was not very efficient and dumped more fuel down into the crankcase than was really needed, this excess fuel went past the piston rings and mixed with the engine oil which caused dilloution of oil it acted like sandpaper on glass on bearing surfaces and carbon build-up which was responsible for burnt valves,then the early PCV systems also had problems it was not well managed and also let much dirt into he engine oil and intake systems this caused many good engines to expire way too early,since they went to computerized fuel injection and sealed engines the dumping of gasoline into the oil and stopping the majority of dirt into the engine we really do not need unnecessary oil changes it costs money and oil that we need not use,depending on the vehicle and its use 6-9000 normal use oil changes is within reason with reasonable care vehices today have no trouble going 250-300,000 miles these days and save a pile of bucks.....

promechanic

I've been in the maintenance industry for many years. Although I would never do it, there are some "Quick Lube Change" facilities that promise "Synthetic Oil" (in compliance with many auto manufacturer recommendations) but actually refill your engine with cheap, non-synthetic oil. They will, however, charge you full price for the synthetic oil that you thought you were getting.
This is just one of the "non advertised" reasons for putting the 3000 mile reminder sticker on your windshield, as it is not a good idea to expect more than that from the cheap oil that is in your engine.

timo46

I have been changing oils for 50 years...Some of the oils are of a high enough standard they are good for long time...I learned in 1987 the oil I was using was not good enough the tail pipe blew smoke and the auto lacked power to adequately climb the hill to my house....A mechanic suggested I change the brand of oil I had been using and get one of the top 10 brands tested by independant labs...I did and the engine regained power and the smoking quit. That was enough to convince me some oils are suprior to others...Listen to your engine and if you hear noises now consistant with smooth motor operation -change the brand of oil to see if that eliminates noises...I fully appreciate that mechanic...Change the oil when you can see the dirt on the dipstick and listen for ticks when you start the engine[there should not be any if the oil is adequate quality.

timo46

be sure of the quality of the oil...some oils are not good enough for the new high tech engines...check with an independant test company

jbaran888

This article presents some misleading information. Yes today's engine oil technology has progressed from what was used years ago and provides greater breakdown resistance. Today's engines also have higher demands than those of the past due to the increased operating temps for higher efficiencies, wider use of turbochargers, etc. When people bring their vehicles in for an oil change they also get the other crucial fluids and systems of their vehicle looked over. Think: when was the last time YOU checked your oil or something as simple as the tire pressure in your vehicle? Most people won't think to look at anything until something goes wrong, and in most cases, these failures cost more money than a preventative maintenance such as a $30 oil change. Anyhow, most people will knowingly drive over the recommended 3,000 - 5,000 mile interval. I know because I've worked as an auto mechanic for 8 years, and have seen the results of people running their engines out of oil due to leaks or engine consumption and also have other problems that could have been prevented. Oil technology has increased to the level that might allow you to drive longer between change intervals, but is it a good idea? I think I'll keep changing my oil every 5,000.

the570z

I do wish writers would bother to contact a mechanic or two before writing pieces like this. As one who has been in the field for a while Id like to share a couple pieces of insight. First the longer oil change intervals are a result of several things, the article was correct in stating that new oil technologies and cleaner burning engines allow for longer intervals in most cases. The other driving factor in longer oil change intervals is the consumer reports Cost of Ownership index. Car companies know people are very concerned with maintenance costs and they have stretched the intervals of EVERY service to the absolute limits and in many cases beyond them! I am a BMW master tech so I will use them as an example. BMW's service interval is displayed in miles but it is actually based on fuel usage(contaminates from burned fuel is the primary factor in oil wear). Its a very smart system and in most parts of the country it works fine. Out here in the Nevada desert however it doesn't work, partly because customers routinely miss their service intervals by around 10%(if its 3000 miles they come in at 3500, if its 15000 they come in at 17000...) and partly because the heat and fine dust out here put the engines under far more punishment then usual. You cant blame the car companies for not being able to compensate for such things, they cannot base the entire worlds oil change intervals on people who live in death valley as then it would be wasteful. The other thing is with the reintroduction of turbocharged cars oil life can vary massively based on how much time the turbos spend spooled up(at rpms of 50k+). If you drive everywhere with the engine rpm high enough to keep those things spinning you may not waste gas but you burn your oil badly. I have seen several cars that have not missed an oil change with enough sludge buildup to cause engine failure in less then 60k miles. As with anything in life there are exceptions to the rule, blanket statements like "you should always follow the oil change interval in your owners manual or on your dash" should always be followed up with the advice to take where you live and how you drive into account as well. Also there are great variations in quality of oils, if you want to use your factory oil change interval, use the factory oil!

84bobtail

There are a lot of variables in oil life including dust, loads, outside temp, etc. My GMC oil monitor goes quicker the colder it is outside. Having your oil analyzed even once or twice could tell you a lot about what is happening inside.