Very helpful column on knowing when it’s time to change oil. However, you did not address “quantity” in the column, just the algorithms for oil quality. Can I assume that we still need to manually check oil levels, say before long trips, even if oil life is still well above 20%? I ask this so people don’t get the wrong idea that with levels above 20%, they still have plenty of oil. Or is quantity a part of the algorithm?
Even if you have a car that uses an OLM (oil life monitor), you still need to check the oil on the dipstick periodically (I check every week or two). And you should definitely check before long trips and during them as well
Yes. The oil life has nothing to do with the level. You could lose all your oil after a botched oil change when the oil life is 100%, for instance.
Quantity is NOT part of the algorithm. The OLM measures the estimated life of the oil still available till it needs to be changed.
Yes, you still have to check the dipstick periodically, preferably once a week or so.
20% refers to the “life” of the oil left as percentage, it’s not an exact science obviously, but it’s based on the number of cold starts the engine has had, the numbers of miles accrued, the total number of hours the engine has been run, and the amount of time that has elapsed since the last oil change. The amount of oil in the engine has nothing to do with the number (percentage) give by the OLM.
It is not. It’s responsibility of the vehicle’s operator to check the oil level regularly.
I thing the reason that Subaru gets a lot of oil burning complaints is because they have a light that comes on when you are a quart low, which I think is a great idea.
A LOT of cars are probably a quart or more low when they go for an oil change but go on in blissful ignorance until it get so bad that the engine blows, claiming the car suddenly lost all it’s oil because they just don’t thing they should have to check the oil.
Like others have said already, check your oil regularly. Oil quality has nothing to do with oil quantity. I have no idea how so many people have confused this issue. You need to check your oil regularly, and you need to change it regularly. Engines burn oil. There’s nothing new or unusual about that. Your owner’s manual clearly directs you to check the oil level regularly. Not before a long trip, not when the oil life monitor gets to 20%, but regularly.
I suspect most people here clean their toilet once a month. Checking the oil in your car is easier, takes less time, and is far more sanitary. A new toilet costs a fraction of what a new engine costs. Yet people take better care of their toilets than their cars.
Oil quantity and quality are related in one sense.
In an engine with chronically low oil level the oil that’s left has to work harder, and will be exhausted sooner.