Is it Normal for a New Car to Burn Oil ?

[Eric Danstrom]

I have never heard of engines being designed to burn oil that's a new one on me. Even if this is true, what the poster is describing is way over the top .....

You almost got it right. Yes, engines are designed to burn oil, all of them do it to some degree. But the question is how much is acceptable. (I promise you even your best and most favorite engine burned some amount of oil, it's the nature of gasoline power piston based internal combustion engines.)

Here's the larger explaination; in the never-ending quest for better gas mileage, manufacturers have chosen newer design criteria for piston rings. These days engines have looser rings to increase gas mileage. The unfortunate result is that a certain percentage of these engines burn oil at a higher rate than consumers expect. All the manufacturers I am familiar with consider anything over 1qt per 1000 miles as acceptable and inside the specification. If your engine burns a quart per 1000 miles you're stuck. Use the Google if you don't believe me.

[Eric Danstrom]

Here's a good link:
https://www.bellperformance.com/blog...ered-excessive

With the consumer demand for more fuel efficient vehicles, there have been a couple of engine changes that influence the answer to this issue. These changes have affected the amount of oil an engine will consume by burning it and still be considered acceptable.

One change comes from changes in the piston ringers for the sake of fuel economy. The highest friction point in an engine is the point where the piston rings are in contact the cylinder walls. The higher the ring tension, the more efficient they will be at scraping oil off the cylinder walls on the downward stroke of the piston. In order to reduce friction and achieve additional fuel economy, the auto manufacturers have reduced the piston ring tension. This ring tension change has resulted in small amounts of oil getting past the piston rings into the combustion chamber where it is burned. This is the primary cause of normal oil consumption in most properly-serviced vehicles.​

[michael langman]

It doesn't make sense to me. If an engine is using oil then it is polluting the air. The whole purpose of better gas milage to reduce pollution, to allow us to put a quart of burnt oil into the atmosphere sounds ridiculous to me.
If I put a quart of oil into my engine every 1000 miles, then in 100,000 miles I am burning 100quarts of oil,divided by 4 is 25 gallons of oil!

[Robert Engel]

Eric I think you are referring to thinner rings, not looser rings. Motors burning excessive amts OD oil are defective, period.

Michael, you’re making too much sense!

[Eric Danstrom]

Eric I think you are referring to thinner rings, not looser rings. Motors burning excessive amts OD oil are defective, period.

Michael, you’re making too much sense!

The cited article I quoted calls the rings as "reduced tension" not "thinner" as you claim. The change and it's effect are well known. And rings haven't needed to "break in" for at least 4 decades.....

[Eric Danstrom]

It doesn't make sense to me....

I'm not arguing the point. I am explaining how modern engines with looser, reduced tension piston rings can have relatively high oil consumption and still be considered inside the specification. It's a fact and op is stuck with his car and will receive no consideration from the manufacturer.

[Larry Frank]

I do not know about the ring issue. But, I have two new 2018 cars and they burn almost no oil. If I were looking for a new vehicle and reading reviews and complaints, I would stay very far away where burning that much oil is considered normal.

[Chuck Wintle]

We have a 2019 car with 11,000 miles on it that's my wifes. We it bought new from a dealer. First oil change was at dealer at 5k as recommended. No idea if it was low as I trusted a new car not to burn oil. At 7k mi a low oil light came on. It was a quart low! I added proper spec oil. Now 1k mi after the 2nd oil change its a quart low. No drips or leaks. The local quick lube who did the 2nd change is a friend and he and I are both mystified.

I googled it and found:
https://www.consumerreports.org/cro/...tion/index.htm
Subaru considers a quart burned every 1,000 to 1,200 miles to be acceptable! Audi, BMW, and Subaru stick firmly to the statement that oil consumption is a normal.

Consumer reports says Subaru is wrong. I'm ready to insist Subaru fix the problem.

Any feedback is appreciated. Thanks

As was mentioned in another post make sure the problem is well documented by the dealer as well as yourself. check the oil level often, record the mileage etc. If there is a problem with rings or some component it will not get any better. Have you investigated for leaks etc.

[Robert Engel]

I'm not arguing the point. I am explaining how modern engines with looser, reduced tension piston rings can have relatively high oil consumption and still be considered inside the specification. It's a fact and op is stuck with his car and will receive no consideration from the manufacturer.

I understand what you're saying, but the reality is none of my vehicles even come close to burning that amount of oil.

1 quart per 1000 miles means on a lot of cars you never would even change the oil, just the filter

[michael langman]

Rings come in sets of three. The top ring is the oil ring. This keeps the oil from getting by into the intake,exhaust valves. That is the ring that causes oil consumption because it is letting the oil go by by being looser and thinner.
The 2 lower rings do not let oil get by because they act as a hydraulic cylinder. If that much oil got by that is burning a quart in 1000 miles then the engine would have compression problems. If those rings are leaking then their is something wrong.
I would run a thicker oil in the engine. If this helps the oil consumption then the thinner oil might be getting by the compression rings.

[Chuck Wintle]

Rings come in sets of three. The top ring is the oil ring. This keeps the oil from getting by into the intake,exhaust valves. That is the ring that causes oil consumption because it is letting the oil go by by being looser and thinner.
The 2 lower rings do not let oil get by because they act as a hydraulic cylinder. If that much oil got by that is burning a quart in 1000 miles then the engine would have compression problems. If those rings are leaking then their is something wrong.
I would run a thicker oil in the engine. If this helps the oil consumption then the thinner oil might be getting by the compression rings.

I will disagree with your suggestion to run thicker oil. That very likely would void the warranty if they needed an excuse to do that. Also the top ring is a compression ring. the oil control ring(s) are lower down on piston body..

[Andrew Joiner]

As was mentioned in another post make sure the problem is well documented by the dealer as well as yourself. check the oil level often, record the mileage etc. If there is a problem with rings or some component it will not get any better. Have you investigated for leaks etc.

No leaks or spots on our driveway.

Shortly after the first oil change by the dealer a low oil light came on. It was a quart low and I added synthetic oil as specified. My wife reported that to Subaru by phone only. I checked the oil often after that.

Now with the second qt burnt on the second oil change I was alarmed. She took it to Subaru and they put in a qt free. I was surprised to see the receipt when my wife got home. No mention of anything unusual. My wife is more trusting of sales people on these things and it is her car. Now I'm doing all the talking and documenting with Subaru. We're getting the Oil consumption test done this week.

[andy bessette]

I will disagree with your suggestion to run thicker oil. That very likely would void the warranty if they needed an excuse to do that. Also the top ring is a compression ring. the oil control ring(s) are lower down on piston body..

This I agree with.

[Kev Williams]

First oil change was at dealer at 5k as recommended. No idea if it was low as I trusted a new car not to burn oil. At 7k mi a low oil light came on. It was a quart low! I added proper spec oil. Now 1k mi after the 2nd oil change its a quart low. No drips or leaks. The local quick lube who did the 2nd change is a friend and he and I are both mystified.

I've asked this once, I'm asking again: Did you check your oil immediately after your oil changes?

I'm curious because what we know is: the first quart of oil missing was 2000 miles immediately after the first oil change, and the second quart of oil missing was 1000 miles after the second oil change?

What I/we don't know is, after YOU topped off the oil and assured the pan was full, how many miles did it take to burn ANOTHER quart of oil?

If you've mentioned this and I missed it, my apologies-- if not, my point is simply this: did those who changed your oil actually fill it? As I mentioned in my prior post, more than once immediately after an oil change I've found the level to be low....

[Chuck Wintle]

I've asked this once, I'm asking again: Did you check your oil immediately after your oil changes?

I'm curious because what we know is: the first quart of oil missing was 2000 miles immediately after the first oil change, and the second quart of oil missing was 1000 miles after the second oil change?

What I/we don't know is, after YOU topped off the oil and assured the pan was full, how many miles did it take to burn ANOTHER quart of oil?

If you've mentioned this and I missed it, my apologies-- if not, my point is simply this: did those who changed your oil actually fill it? As I mentioned in my prior post, more than once immediately after an oil change I've found the level to be low....

I would add as a caveat to have the car on a level area and check when the engine is cold as it takes some time for ut all to drain back to the oil pan.