Mobil-1 EP, around 8 year old Sienna with well over 150,000 miles, and mostly driven on the highway long distances. All parameters, including contamination, additives remaining, were good, and indicated they would stay good until an estimated 10,000 miles.
All that proves is that for YOUR vehicle and YOUR driving conditions the 10k mile oil change interval MAY be good. That does NOT mean you can apply it to all vehicles under all driving conditions. So saying the 10k mile oil change interval is valid for all vehicles at all times is only a guess.
Personally I’ll risk MY vehicles/money on MY guesses…NOT YOURS.
I’d guess that 95% of our daily decisions are pretty much guesses not based on hard fact. I can live with intellegent guesses. Having motor oil tested is fine and makes money for the testers but you are assuming the
testers are competent, and that conditions from one change to another are consistent. That’s kind of based on guessing and faith not fact. And the monitors are not based on actual fact but on guesses of what the oil should be like after so many miles and so many start-ups. I’ve lived long enough to see many things consided fact one day become myth the next day so I’ll just keep on doing what I’m doing regardless of what some California environmentalists say. I’m not impressed with California or their government and that’s a fact.
There are too many variables in driving styles, engine loadings, and weather for someone to make a simplistic statement. Even oil life monitors don’t know what is in the crankcase, whether the eninge has blowby, whether the PCV valve is working properly, etc.
irlandes is right in testing his oil and seeing if his driving pattern allows a longer oil change interval than the manual (5000 miles). Since he is in the South and does a lot of highway driving, the 8800 mile interval on his Sienna is OK. If he lived in Minneapolis and parked outside without a block heater, and drove a short distance to work, where he also parked outside, the 8800 mile stretch would soon sludge up his engine. That’s why Toyota puts 5000 miles in the manual.
In industry, maintenance is treated as a site-specific and operation-specific activity. Maintenance is not a “one-size-fits-all” activity. Ask any army or airforce mechanic.
Regardless what the California govt. says, each driver has to read his manual and then adjust it for his driving style.
Bing — "And the monitors are not based on actual fact but on guesses of what the oil should be like after so many miles and so many start-ups."
Oil condition monitors do not consist of mathematical algorithms based upon mileage and start-ups. They are sensors that measure such things as the dielectric constant of the oil. I think they know more about the condition of the oil than most owners.
As for when to change oil, no one on this board has any background in automotive or chemical engineering. One may as well walk into Walmart and ask the first customer one sees for their recommendation on oil-change intervals. This board is funny at times.
I change oil twice a year–after spring commencement and after fall commencement at my institution. Since I have to wear my cap and gown anyway, I might as well put them to good use after the ceremony is over.
I have a friend with a late 80s Buick with a V-6, he bought it used. He NEVER changes the oil, only the filter every 2000 miles, tops off with whatever he loses when he takes the filter off. His theory is more and better filtering is better. He’s been doing this for over ten years, it still runs pretty good for a 25 year-old car. Maybe we’ll come to a point when we never change oil anymore! Rocketman
“Oil condition monitors do not consist of mathematical algorithms based upon mileage and start-ups. They are sensors that measure such things as the dielectric constant of the oil”
Its possible that there are such oil life monitors, but I doubt it. None of the ones I know of measure anything about the actual condition of the oil - i.e. there are no sensors for it. All the computer does is keep track of various engine operating parameters since the OLM was last reset. There is no direct knowledge of the oil’s actual condition. You could reset an OLM without changing the oil and the computer won’t know the difference. In fact, I own a vehicle that spent its life on the OLM and based on what I can see inside of the oil cap I have to conclude a) that I will never trust an OLM or b) that the shop the previous owner of this vehicle always used should not be trusted. More than once I’ve been led to wonder whether their version of an “oil change” was to send someone to the parking lot to reset the monitor and then just total up the bill for an “oil change.”
Oil will deteriorate. And regardless how well filtered, deteriorated oil will hasten the demise of an engine. Stuck rings, galled cylinders, jumped timing chains, camshaft lobe and valve train wear, etc, ad nauseam, are premature failures that often occur with the telltale markers of heavy shellacking, sludge, deteriorated seals and sticking hydraulic lifters. It would seem that the manufacturer’s recommendations are reasonable but I play it safe and service my vehicles at 3,000 miles.
cigroller is right; today’s oil monitors on cars go by driving pattern, such as starts, stops, length of trip, etc. THERE IS NO ONGOING CHEMICAL ANLYSIS OF THE OIL!!!
GM, about 10 years ago, developed an experimental oil analysis kit that measured constantly crankcase oil acidity and a few other parameters. It worked quite well, but would have been too expensive (and perhaps troublesome) compared to the OLM offered today. If you had water in the crankcase or cooking oil, the OLM would function exacty the same. That’s why I advise every driver with one to use it as a general guide; I would change oil at 50% remaining oil life, just to be sure.
It’s been thoroughly tested and used for 30 years. Most (all?) of the auto manufacturers use them now. I have a hard time believing that there is anything wrong with using the OLM.
Many years ago, after researching this subject and reading as much as I could get my hands on , I came to the conclusion that the correct answer for the interval of changing oil, types of oil used and the type of oil filter, is whatever makes the owner of the vehicle sleep better at night. Whenever I have this discussion with a friend of mine, I can’t argue with him when he tells me he buys the cheapest oil and filter he can find and changes it every 7500 miles. He’s had no engine problems in the 40+ years he’s owned cars - NONE. But me personally, I have to change my cars every 3K miles with only a certain brand of oil and certain brand of filter. Why ?? The only logical reason is I sleep better at night - no valid reason at all !
ebko; we have a fact and fictionsituation here. Many years ago you indeed had to change oil every 3000 miles to get maximum engine life. Now, with vast improvements in engine oil and better engines, we can stretch that interval. Your friend who has not had any engine problems in 40+ years is not unique; neither have I and a lot of posters here.
The two factors here are, how often did your friend trade cars, and what was his driving environment.
I used to drive 40,000 +miles per year, nearly all highway and would have gotten away with changing oil less frequently. Since my cars were new and company owned, I went by the book.
We have many posters who keep their cars to the end of their economic life. Those change oil more often, since they don`t want the car to self-destruct due to engine failure. Those that trade when the warranty is up can go a lot longer since the next owner(s) will have to deal with that. OLMs will definitely allow the car to go to the end of the warranty without major repairs.
So, what allows me to sleep nights; knowing that I`ve tailored the oil change interval to the driving environement and for longest engine life. Engines are expensive, but oil is cheap. The California government does not necessarily have that philosophy and priorities.
Doc…“regardless of what the California govt. says , each driver has to read the manual and adjust…”
Exactly…
According to the articles I have read, that IS what the govt. says…".read the manual and follow the manufacturers suggestions." And “going by the book as” as you practice. I see nothing in the articles that contradicts what we normally give for advice. I am amazed that the post has gone on this long without acknowledging that and continues as a reason for a few to dump on a govt. agency…I thought it was a public service message and not a regulation.
Of course, running fresh oil through a car continuously would be ideal, but the effort isn’t worth the cost. Motors generally outlast the bodies and cost LESS to replace when the do need repair. This is just another illustration of the fixation we owners and contributors have on oil changes…the most over done maintenance of well intended but misguided owners. Like, " changing oil at 3000 miles with no valid reason".
Personally I always change my oil at 3000, unless I have been driving it really hard . . like really dusty, extra hot, something like that. The I go sooner, maybe 2000. I usually get an oil filter for less than $3.00 and a gallon of oil for about $12.00, so the $15.00 is cheap insurance for me. I don’t worry about how ecological I am because I always recycle my old oil at the place where I buy my new stuff. Rocketman
Since I started this post, thanks guys for all the lively and useful comments! My main concern was that someone seeing “12,000 miles” would automatically assume that this applied to his or her situation, and stretch their oil change interval to a dangerous length, just because the government uttered the word.
Agree with dagosa that “going by the book” is better than what most owners do and most certainly better than guessing.
Whether this is a “public service” announcement is debatable; the focus here is on reducing waste oil and not necessarily lengthening engine life or saving Californians money.
Ther’s no need to close off the discussion at this time.
“Engines are expensive, but oil is cheap. The California government does not necessarily have that philosophy and priorities”
I disagree. Cali did a study to determine how they could save money for their citizens. They had motor pool vehicles that they changed the oil according to their old practices, and others that they changed oil according to the OLM recommendations. They later disassembled engines to see if there was a noticeable difference, and they could find none. Since they found that they could both save money by changing oil less often and reduce oil disposal costs, they thought they would pass that information along to their citizens and anyone else that reads their info on the web.
FWIW, I took a quick look under the hood of a friends 2005 Corolla today. It has clocked 140,000 miles and gets serviced every 5,000 miles with 10-30 synthetic. The oil was near the full mark and nearly clear with 2,000 miles and with the engine running, removing the oil fill cap required overcoming the vacuum from the crankcase ventilation plumbing, indicating that the venting is open and the compression loss is minimal. I was reassured that all was well but reminded that it seems apparent the crankcase ventilation system is a key factor in the extended life of engines in recent years. I would venture that improved oils and the PCV system has as much to do with greatly extended engine life in modern cars as the improved tolerances in manufacturing.
Jt…Thanks. A breath of fresh air in this discussion. Unfortunately, old habits, even the useless ones, die hard. Let me add that there are a plethora of things we should do to a car more often than change the oil.
Like, air pressure check, suspension and steering linkage check, cv boots, all fluid levels, torque wheel lugs, tire tread depth for unusual wear, body perforation checks in the rust belt, drive belt condition, battery terminal maintenance check, touch up nicks and scratches, etc. if you are changing your oil more then these and other checks and maintenance, you have your priorities skewed up IMO.
Jt; that’s good news indeed that the government actually had a long term interest in mind. Most California driving is in mild weather and with good freeway runs. This driving is very easy on the oil, and can easily stand a recommnednded increase in the change interval. As long as someone in North dakata who parks outside does not literally adopt it, I’m in agreement with their recommendations for most California drivers.
Like most here , I resent the litle 3000 mile change stickers that the rapid lube guys stick on your windshield.