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How long can you avoid changing full synthetic oil

I have a 2011 honda accord that takes full synthetic 0w-20 oil. I use honda brand full synthetic oil and don’t drive this car that often. I do take it a few miles a couple times a week to exercise the engine. It has 15,000 miles on it now. According to my manual I should change the oil every 7,000 miles and it has an indicator light when it’s time to change the oil. If I was to use mobil 1 full synthetic I could in theory wait until it has over 15,000 miles. I have only put on about 3,000 miles since my last oil change which was over a year ago by a few months. I checked the oil and it is still a nice golden yellow color and the oil level is normal. Can I wait until I have at least 7,000 miles on it to change the oil even if it is 1.5-2 years as long as the oil looks clean and the level is good?

Does your manual say to change it every year? If so, I recommend doing that. Regardless of the oil type, it gets contaminated over time, especially if you make only short infrequent drives, and you don’t want that oil sitting in there for too long.

That is actually the worst thing that you can do to your engine, as well as to your exhaust system.
If you want to “exercise” the engine, you need to get the engine up to full operating temperature and then to drive for over 30 minutes in order to evaporate all of the accumulated water condensation that has been deposited in the motor oil as a result of all of those short trips.

When you don’t evaporate all of that water condensation, it turns acidic over time, and leads to deposits of damaging sludge in the engine.

All of that being said, I would recommend that you not go longer than one year before you change the oil.
Simply “looking clean” is not an accurate indicator of how contaminated or acidic that oil may have become because of the short trips and infrequent oil changes.

Ask yourself this question:
Would you wear the same underwear for several days, simply because it “looked clean”?
Just as good personal hygiene dictates daily changes of your underwear, good engine hygiene dictates much more frequent oil changes than you are contemplating.


The oil life monitor (OLM) will tell you when you need to change your oil. Oil does not degrade while sitting in the pan. If you are only driving a few miles (less than 7) on each start up, the OLM will take that into account and turn on the indicator sooner.

I do recommend that if you are only exercising (? it’s not a horse) the vehicle, drive at least 7 miles, 10 if below freezing.

Check the manual it might say change oil at 7000 miles or once a year . That only makes sense .

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But I don’t think the OLM is hooked up to a calendar (at least, the one on my Acura is not), so it has no idea that OP has gone for over a year without changing the oil. OP should have the oil changed at least once per year.

Just pretend its dino oil and change accordingly. You should not extend oil changes just because it is synthetic. It was a common marketing theme to get people to buy. I change mine at 5000 miles with 0-20 Mobil 1. If I didn’t put 5000 miles on in a year, I would change once a year. I pay about $25 for 5 quarts of Mobil 1 and $5 for a Honda filter. How much did you pay for the car compared to the cost of an oil change?

I do not agree with you. The engine is sealed up pretty well so when the oil is just sitting in the pan, its not much different than sitting in the bottle on the shelf.

The miles/months interval assumes the vehicle is driven daily and the low miles is due to short trips, which are harder on oil. The OLM will take in account the short trips, but if there are only a few short trips a month as oppose to a few every day, the oil can last for many years.

Since I retired my 97 Nissan PU from daily driving chores and only use it for garden and house projects once or twice a week, it gets an oil change every 7500 miles, or about every other year. Sometimes longer. No ill effects yet and its near 200k now. I retired it at about 140k in 2002.

Sealed up has nothing to do with it. OP is driving it a few miles a couple of times a week. Condensation is forming, and not getting burned off because OP does not drive it enough, and that condensation is sitting in the oil (and everywhere else). That’s bad, and the oil needs to be changed.

Quite frankly with that kind of abuse, I suspect once per year is not enough.

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Still do not agree with you. Oil is the primary coolant in an engine, it is closest to the combustion process. The antifreeze/water handles the bulk of the heat, but the heat goes through the oil before it gets to the coolant. By the time the coolant is up to temp, the oil is hot enough to evaporate any water in it.

Many people are under the misconception that as soon as the motor is shut down, condensation immediately starts to form. That is not true. The amount of moisture in the air trapped inside the motor is the same as outside. Condensation only occurs when the air temperature goes below the dew point.

If there is no dew on the paint, there is no condensation in the engine. Once the dew evaporates off the paint, it evaporates in the engine also.

Besides, we don’t really know what the OP’s definition of a “few miles” is.

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Keith-My personal opinion is that your dead wrong. I believe condensation and dew are two different things . If you want to use your choice for time to change oil fine. But offering that advice to a complete stranger not knowing where they live, driving habits and their mental comfort level just sounds wrong.

Oil change interval cannot be extended just because you switch to synthetic oil. The amount of additives in the oil determine when the oil begins to break down in normal driving conditions. Synthetic oil might have more buffering additives, but it doesn’t have to have more than typical mineral oils. Synthetic oils stand up better to high temperatures, and in that sense it resists break down. If you don’t use the car much, just use mineral oil of the correct grade. Mineral oil has been used for decades without problems. I see no need to spend extra just because you can.

Dew and condensation are exactly the same thing. The definition of condensation (occurs when the temperature of a object goes below the dew point) does not change for automobiles.

Do you believe that the only advice that should be shared here is advice that you agree with?

I do not share your personal opinion, but as far as I am concerned, you are welcome to share it. You and I may not agree on this subject, but the OP came here for opinions and I’m pretty sure they expected to get different opinions.

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If the manufacturer specifies 0-20 synthetic oil, then the OLM is calculating the oil change interval based on that oil. Using anything could result in engine damage if the oil breaks down sooner than the OLM predicts.

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So…you are suggesting that it is better to use…nothing?
You may wish to differ, but I think that even the wrong specification oil would be preferable to…no oil.


FWIW I have a few firearms that just sit in a large gun case. At least once a year I pull them out to clean and lube them. A few years ago as I again found several actions sticking I left the Hoppes on the shelf and used some synthetic oil that was handy. The next year the actions were just as gummed up as they usually were. My conclusion was that the stuck valves on lawn mower engines that sit unused all winter would be just as likely with synthetic oil as with dino oil and automotive engines that sit unused for long periods shouldn’t have periotic maintenance extended due to the improved performance of synthetics. I must assume that everything that can get gummed up, i.e., rings, chain tensioners, chain links, roller followers, etc., is apt to get gummed up sitting unused regardless of the quality of the oil. And personally I am an advocate of starting and running engines up to operating temperature every few weeks and driving cars until fully warmed up regularly. But as they say, “to each his own.”

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How does the oil life indicator on my car work? Does it measure things like acidity, oil breakdown, and carbon in the oil?

I can’t answer the question about how the oil life indicator works but I recently bought a 2016 Honda Fit and the manual says to change the oil when the oil indicator tells you to or 1 year - whichever comes first.

This first year I don’t think the indicator will tell me what to do and I will change it after a year (January). Afterwards, since I don’t put a lot of miles on this car, I intend to change the oil every 6 months like I do with my other cars. That’s half of the time that Honda recommends but I feel better knowing there is fresh oil every 6 months rather than waiting a year. The manual says that I can use either 0W-20 Synthetic or 0W-20 synthetic blend.

My point is that if you aren’t putting a lot of miles on your car, you should change your oil at least once per year - and you should absolutely never wait until 15000.

What happens at the 1 year mark to make the oil go bad?

The idea is that after one year Honda believes the oil will still be okay, but not for long afterward, so it’s time to change it.