How do 20,000-mile oils work? Change filter at 10K?

Special oil filters?
Thank you.

Personally, I’m skeptical of these extended change oils, be it 10K or even 20K miles.

Having said that…I’d just stick to changing the oil filter when you do get around to changing the oil.


I think that the oil companies should include a Bible, a rabbit’s foot, and a four leaf clover with the oil purchase, so that car owners can pray and wish for a good outcome with that type of ridiculously-extended oil change interval.



I assume the way they work is that you add new oil and a new filter, drive for about 11,000-12,000 miles, then the oil pressure light comes on, the engine makes loud noises, and you say “oh sh**, I never should have trusted that snake oil”, as you tow your car to the shop for a replacement engine.

Seriously, though, since most engines use some oil–some more than others–the big “catch” of extended oil change intervals is that you still have to check the oil level frequently, and top off as needed–which negates any “benefit” from the long oil change intervals. At least when the oil change interval was every 3,000 to 5,000 miles, most people never ran out of oil unless their engine was on its last leg anyways.


They work for 3-4 oil changes…then you’ll need a new engine.


To me, these 10-20K miles oils are either a), a solution in search of a problem, or b), an excuse for people who just can’t be bothered to change their oil at regular intervals.

Personally, I want fresh oil (and a filter) in my engine a couple of times a year. It’s cheap insurance for the engine’s useful life, and I plan for it accordingly (the oil changes).

It’d be different if suddenly there was a shortage of engine oil, and we all had to extend to 10K miles. But last I checked, you can get a 5 qt jug of Mobil 1 synthetic for under $30.

The older I get, the less I seem to understand other people.


I imagine that after about 10 or 15k miles, they work similarly to homeopathic medicines. :wink:

If you dilute oil with dirt and gasoline, it becomes even more oily! Oil has a memory. It remembers when it was clean and so it behaves as though it’s clean.


BrianH UK

I think it is down to cleanliness of the oil. Less you keep the oil clean the more it grinds the bores out. My redblock Volvo engine at 500k miles used 1 litre per 5k. The compression was reducing but still in specification. Using bypass filtration, down to 1micron, and 0/30 fully synthetic oil. The oil was sampled every 6 months and sent to a lab to be analysed. Using the lab advise I changed the oil from 70 to 150k!!!
These items to achieve this were purchased in the USA.
Manufactures want to sell new cars.

BrianH Volvo 245 760k LPG

Its down to oil keeping the oil clean. Get down to 1 micron with by-pass filtration.


If I’m correct by this, your Volvo uses Propane? If so, I’m not surprised that your analysis shows that you could go years between changing since Propane burns so much cleaner than gasoline does. While that’s excellent for you, that is unfortunately, irrelevant to engines that burn gasoline.


Propane burns much much cleaner than gas. City Bus’s that switched to Propane or Natural Gas have been able to triple their oil change interval. You can NOT compare oil cleanliness from a vehicle that runs on Propane to an engine that runs on gas.

I drive 6-7 thousand a year on my 2012 Camry. It has 54000 on it and I change it once a year and the oil stays so clean I have trouble reading it on the dipstick.

I buy whatever name brand full synthetic is on sale or has a good coupon, usually Mobile One or Pennzoil but this last time there were no coupons so I bought a 6 Qt box of Havoline for $19.99. I changed it Aug 8 and it is still so clear that the only way I can read the dipstick is to lay it on a paper towel.

If I was driving 20,000 a year and was out of warranty, I might try an oil that promised 20000 miles because that kind of driving is pretty easy on oil, but I would not go longer than a year.

The trouble is, unless you are operating a fleet, you have no way of gathering real evidence to support what you believe about oil.

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I agree…I essentially said that in my post. Unless you were talking to @Brian-236?

I was agreeing with you

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I am puzzled.
Does that mean those engines that contaminate their oil with carbon are less likely to run much past 150k before failing?
Diesel engines seem to out last petrol.don’t you think?

Not in cars, they don’t. 1M miles on a truck diesel is not uncommon. Generally uncommon to get a car diesel past 300K miles. Getting 250K miles on a gas car engine is easy and fairly common in the US. Many posters to this site have seen 400K and more on gas engines in cars.


Aren’t diesel engines far “heartier” than gasolinengines?
Friend owned a 1964? Chevrolet CarryAll whichad a diesel engine block with engine running on gasoline.
Never had anything done to it and it attained high mileage.
(It also had the toilet paper oil filter and the oil always looked clean.)

Not the same dilution rate. Some of those rigs can hold 10+ GALLONS of oil. The oil does get contaminated, but the dilution would be far lower due to the amount of oil. By comparison they typical car engine takes 5-6 quarts.

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Yeah, it’s a myth that car diesels far outlast car gas engines. I read an article about a million mile Mercedes diesel. Turns out he had the engine rebuilt every 250,000 miles.


Cars that have that interval have large oil sumps. That means they have a lot more buffering additives than for a similarly sized engine with a smaller sump. My guess is that you are thinking of European consumer vehicles with very high oil change intervals, like BMW and Mercedes Benz. You also use the specific grade they recommend so that there are sufficient additives to need the demands of a long change interval.