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Outback is using too much oil - Subaru disagrees

I have a Subura Outback 2014 2.5L. It uses about a quart every 1500 miles. Subura refuses to fix it and I have heard from other owners that even replacing the short block of the engine does not remedy the solution. They thought it was the piston rings but say its not. We bought the car brand new in 2014.

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There’s a lot of people that wish that got that good of mileage out of a quart of oil.

You can complain all you want, but 1 quart in 1500 miles is not considered excessive by car manufactures.

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Perfectly normal for a Subaru and many other brands. Nothing to complain about.

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And so would every other manufacturer.

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My sympathies. It’s perfectly acceptable to judge a car maker’s manufacturing excellence by its oil mileage. The goal in short block design should always be zero oil burning. That shows precision in the machining process and high quality of metallurgy and piston rings. The goal of some owners is to get 200K miles from their car and that’s going to be tough to do if it’s burning oil when it’s new since oil burning generally increases with age.

You’re no doubt aware of Subaru’s reluctant post-warranty agreement to replace defective piston rings in certain model-years but unfortunately that doesn’t help you.

I don’t know how accurate this is, but I’m pretty sure I’ve read here more than once that many manufacturers consider one quart per thousand miles to be the limit for acceptable usage.

Audi claims that the consumption of 1 qt. per 600 miles falls within its definition of “normal”.

They should put that in the sales brochure.
“The new 2019 Audi A3 250 hp and only uses a quart of oil every six hundred miles”

Audi only reveals that judgment when people complain of excessive oil consumption.

I wouldn’t be pleased with that amount of oil consumption, but I agree that it’s not a warranty issue for the carmakers, and as long as you check and top up and change the oil as specified, the engine can go on like that for many tens of thousands of miles.

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I have to disagree with my fellow Community members here. Consuming any oil is not “normal.” For any car. Subaru says that it occurs on just 2% of its vehicles, and yours is one. 98% have no oil consumption. That is the normal situation. What you are describing is a four-year-old car that consumes (or would if you let it) all of its oil between oil service intervals. Calling that normal makes absolutely no sense and a CYA statement in a manual doesn’t change that. All you can do is keep documenting your oil consumption. As you (Hopefully) already know that engine has a well-known defect that causes excessive oil consumption leading to engine failure. Subaru settled a class action lawsuit that includes your model and year vehicle. Dealer push-back and Subaru dodging the issue is typical, but many owners do have their vehicles repaired in the end. The short-block replacement does not always work, but often does. Subaru does not know how to stop the issue, or it would. Here is a detailed CarTalk story on the subject. The class action info is linked to in the story. Best of luck. Form a fellow Subaru owner and one whose past Subaru legacy engine failed at 11K miles.

Well, technically, engines must consume some oil. The purpose of the oil control rings is to leave a thin film of oil on the cylinder wall to lubricate the compression rings. Those get really hot and vaporize some oil and some slips by the ring end gaps and gets burned that way. The difference is that many engines use minuscule amounts of oil and that can be replaced by combustion byproducts such that, in-between oil changes, it appears there is little to no consumption.

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I don’t argue the theory, but I have owned over 20 vehicles including one that was over 20 years old. None consumed any oil that could be measured on the stick between routine oil service intervals. The idea that any car would consume oil so fast it would use up its entire volume between the oil change interval is absolutely absurd. I understand the mechanics here see cars that consume oil. That does not make it normal or acceptable. Particularly in a year make and model known to have an oil consumption defect that the automaker has agreed to deal with.

Picture in your mind a bell-shaped curve. That higher region, not precisely defined, includes most of the population of engines. They consume some, not much, oil. To left and right are regions with many fewer members. Those have a lot more and a lot less oil consumption. The output of any manufacturing process, when analyzed by whatever criteria, will tend to fit the bell-shaped curve. Manufacturers define “normal” to include all but the very few engines at the farthest departure from the hump on the curve. It’s how things are and it doesn’t represent any wrongdoing.

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I am specifically addressing your assertion that normally cars do not use any oil. It’s not a theory btw, it’s a fact. An indisputable one as it uses some oil by design. You may not believe it but that does not change the physics of it. You have also been lucky enough to have every engine you have owned that seem to be within the best side of the consumption curve. The doesn’t erase the fact that there are tolerances in manufacturing that lead to variation in consumption throughout the population. Cars using oil is definitely “normal” and acceptable. Consumers may not LIKE their cars using oil, but some percentage of the population is bound to use more oil than others. Now, we could have a world where this never happens but I do not think you would like the price increase for your next car…

This is all aside from an issue with design or manufacturing defects that lead to unexpected outliers. You’re lumping the two together and claiming that they are equal. They are not.

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2015 Forester here. I would say its pretty standard for Subaru. Whether it is normal or not is up for debate. That said, I do not need a quart/oil change but I sure fill up at least half a quart between 6000 miles oil change interval.

This is the reason why the manual asks you to check the oil level at every gas fill up.

Not too sure what oil you use but try Castrol Magnatec. Some on Forester boards have claimed that it reduces oil consumption. I have not tried myself so can’t comment on the validity of the statement.

starting with a little over a million (1,048,576 to be exact) persons flipping coins 20 times, and letting the people who flipped heads each time continue, will result in roughly one person who flipped 20 heads in a row

there are many millions of car owners

I have a deep respect for the opinions of other members and the experience of the mechanics in our community. I differ in my opinion the general subject of oil consumption. I understand the physics and mechanics of piston rings and engines. I also know that each manufacturer is more than capable of designing a car that does not consume more oil than would have to be replaced during its oil service interval. Automakers put notes in their manuals about consumption to cover mistakes in their manufacturing process and to keep owners from panicking when the level drops from “full” to below full, but still above the minimum level. I don’t think any theory or statistic can convince me that a vehicle, particularly a relatively new one, should ever be sold with a design that would require an owner to add oil to keep it above the minimum line on the stick. Feel free to try. In the case of this post, this is a year make and model with a consumption defect covered by a class action settlement. The owner is reporting that over 3 quarts will be consumed between oil services. “Don’t worry about it” is not good advice IMHO.

My experience with 5 Subarus my family owned also confirm that they in general use more oil than for example Nissan (huh, I had 5 Nissans in my garage over years too!).

@Wes57, quart per 1500 miles is a little bit more than I observed even in 100K engines, but still it is not bad.

I also consider it not normal and think it is design flaw from Subaru side, but it is what it is when you own one.

Now, to deal with it, I used oil with the smallest evaporation rate I could get my hands on, within the stores around, not going to mail-orders.

Check “NOACK” parameter in oil specs, it must be under 10% for Subaru to be happy and burn less of it.

Catrol Magnatech was apparently suggested by the Subaru users, try it.
In my experience, Valvoline SyperSyn made a trick reducing ~2 quarts between OCI changes burn to under 1 quart burn and no need to add oil.