Subaru Oil Consumption

We bought a 2007 Outback in April of 2012 (~75,000 mi.). After a couple of oil changes I noticed that the oil consumption seemed high. The dealer looked for leaks and replaced the head gaskets under warranty. Oil consumption still seemed high. The dealer started monitoring the oil consumption checking it every 1000 miles for six months or so. Consumption was about 1 qt. for 1200 miles. Reluctantly they agreed to look at the rings (98,000 mi.). They found burnt oil rings and replaced them. Oil consumption went down to 1 quart in 1800 miles (improvement of 600 miles). The engine was still under an extended warranty when this happened. I was claiming that the cylinder bores must have been out of spec to see such a small increase in oil consumption and that they should have given me a new short block or rebored the old one with new pistons to match. My question is, can anyone comment on what kind of a result I should expect from a ring job? Am I correct in thinking that something else must be wrong with the engine if the oil consumption improved so little?



I’ll just say this…you are probably very lucky to only use 1 quart of oil in 1800 miles. There are many new and nearly new vehicles out there that only get 1 quart in 1000 miles. I think a lot of it has to do with the very thin oil that has been foisted upon us just to increase fuel economy. Check your owner’s manual…if it allows for thicker oil grade, like my Dakota does, then try the thicker oil. I changed and my oil consumption nearly disappeared. I live in a temperate zone where the weather is mild year round. What part of the country do you live in? If it’s really cold most of the time…I would stay with the thinner oil and live with a 1 quart consumption in 1800 miles.

This is not a new car. It’s a 2007. The dealer has been more than fair. IMHO your expectations are, by a very large margin, unrealistic.

A quart every 1800 miles for a 7 year old car with 75,000 miles is great. Don’t push your luck. If I owned it, there’s absolutely no way I’d replace or tear open the engine under the circumstances you describe. There’s nothing wrong with it.

I agree with the others that oil consumption on the order of a quart every 1800 miles is nothing to complain or be worried about. Check it once in a while, add oil as needed, and forget about it.

I agree with all of the preceding comments.
The oil usage mentioned by the OP is well within the bounds of “normal” for a brand-new vehicle.
For a 7 year old vehicle with 75k miles on the odometer, this type of oil consumption is actually very good.

I do not see a legitimate issue here.

I would have been happy with both my 1947 Pontiac and my 1971 Maverick if these cars had only taken 1 quart every 1800 miles. My Pontiac used a quart of oil about every 200-300 miles. When you buy a $75 car, you don’t ask if it uses oil, but instead ask "how much oil does it use?"
My 1971 Maverick, which I purchased in 1973, initially used a quart every 300 miles. I had the valve stem seals replaced and it used a quart every 1250-1400 miles. I could live with that. I did find that I would go 1400 miles a quart on Valvoline 10W-40 where I was adding a quart after 1250 miles with Sunoco 10W-40 oil. Some oils seem to give better oil mileage in some cars than other brands.

Over the past few years, we have had a few posts from frustrated owners of new or nearly-new Audis, who were furious about oil consumption of 1 qt ~every 700 miles. When they complained to Audi at the corporate level, they were told that for an Audi to consume 1 qt every 600 miles would be “normal”.

My cars–of varying makes, but all maintained flawlessly–have usually consumed 1 qt every 2k-3k miles. A friend of mine has a 2008 Rav-4 that consumes 1 qt ~every 1,200 miles. Both examples are within generally-accepted “normal” bounds, as is the OP’s car.

And, I have to say again that I do not see a legitimate issue with the OP’s car.

You could ask the dealer and the mechanic who did the work to show you their inside micrometer set or boregauge.
If they can’t produce that then they checked nothing and what you got was a hone job with a new set of rings. In other words, if the cylinders are out of spec then they’re essentially putting square pegs into not so round holes.

Other issues could involve the very tedious task of checking all new ring end gaps, orientation in the lands, sideplay in the lands, etc and the state of the cylinder walls. You state the oil rings were burnt which could mean coked engine oil due to lack of oil changes and/or overheating of the engine at some point.

Sometimes coked oil and overheating has an effect on cylinder walls which won’t be cured by honing.

They will consider this type of oil consumption normal. Not having a vested interest in the outcome, I say that it’s abnormal.
If the engine block had been bored this would have meant a complete teardown and servicing of the crankshaft also due to the Boxer engine design.

This is our fifth Subaru. All of the previous ones were purchased new. They all went 3K miles before being a quart down until the mileage got up near 150K and even then it was still above 2K before we saw the loss of a quart. Regarding the Audi case I have friend who is a service manager for an Audi dealership and he said a lot of Audi blocks were over bored during manufacture and that was the cause of their problems. He was suggesting to me that Subaru might have had a similar problem. I appreciate all of the comments. I guess I might be expecting too much but it doesn’t match my previous experience with Subarus.

You can take two identical engines, both broken in properly, maintained properly, and driven under similar conditions and the oil consumption of one engine may be a quart per 1500 miles and the other will take a pint every 3000 miles. Engines are different.
My brother bought a used 1977 Cadillac that had about 60,000 miles. It consumed a quart of oil every 900 miles. He drove the car way past 200,000 miles and the oil consumption remained at a quart every 900 miles.
You bought the Subaru as a used car. Do you know the maintenance history of the car?
Keep an eye on the oil dipstick, add the oil as needed and you will be fine.

Engines and oils have changed dramatically over the last few years. What the blocks are made of, what the rings are made of, where they are located on the piston are just a few. The viscosity and volatility of the oil, the additives, these too are different from a dozen years ago. Sure, your cars from the past may have used little or no oil. But today you can get 150 horsepower out of a 2 liter engine and see 35 miles/gallon and very low tailpipe emissions. Overall it’s an improvement.

Ase, I have no actual data to reference, but just based on my own experience I’d say that today’s cars on average use less oil than cars of the '60s. The '70s… well, they were known for cars like the Vega, the Duster, the Maverick, and the Pinto. I guess it would be unfair to refer to the '70s… {:slight_smile:

Back in the 1950s through the mid 1960s, when Consumer Reports tested a car, it reported the miles per quart of motor oil consumed after break-in. In 1960, the Plymouth Valiant consumed a quart of oil every 450 miles. Many of the cars tested used a quart of oil in somewhere less than 1000 miles.
Oils and engines have certainly improved over the last 50 years. Fuel injection has helped as the carbureted engines dumped in more raw fuel which diluted the oil and made it burn off quicker. Back in the old days, we just assumed that we would have to add an occasional quart of oil.

TSM, yeah, maybe you’re right. I remember dad always checking the oil and saying that most of his cars didn’t use any oil but in hindsight I remember watching the Texaco station down the street and it seemed like most of the time there was a car at the gas pumps gettinga quart of oil too.

I remember a cousin had a 74 Gran Torino painted like Starsky and Hutch and he drove with a case of oil in the trunk. He said every time he stopped at a gas station it was to check the gas and fill the oil.

With the 5W20 oils these days, a quart per 1000 miles is not that unusual. Last year I rented a Toyota Matrix on a vacation trip. The manual said that oil consumption of 1 quart per 750 miles was “normal”. The oil recommended for this car is 5W20 mineral or 0W20 synthetic. However, 5W30 will work just as well.

Doc, you may have a point. Even as manufacturing gets more precise, the new 5 and 0 weight oils are probably going to offset any gains. It’s an interesting question. At what point does the drive for constantly higher mileage become counterproductive? At what point does an extra .25 mpg gained by using a lower weight oil become higher oil usage?

@the_same_mountainbike–I have a 2011 Toyota Sienna and its gone over 50,000 miles. I use the specified 0W-20 oil and I have yet to add any oil between changes. This includes summer driving at interstate speeds.

I fail to see how countless millions of car consuming countless billions of gallons of oil in what is claimed to be entirely normal is environmentally friendly.

Pick every molecule of gasoline to death, legislate every single PPM, and yet when it comes to oil consumption that is supposed to be considered all fine and well?

Outstanding, Triedaq. I hope the OP doesn’t see that and think he/she should also have zero oil use… }:-o
It’s like being in perfect health at 60; fantastic, but not common.

One thing that I don’t see being mentioned here is with all of the none mechanically inclined people driving these new ‘thin oil’ vehicles who is doing the topping up every 1000 miles? Are dealers actually requesting their customers to come in that frequently? Most of the people I know couldn’t add a quart of oil to their car if their life depended on it.