Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Help! My 2017 Outback Gets Terrible Gas Mileage

I bought a used 2017 Subaru Outback touring, and from what I’ve been able to calculate, its actual gas mileage fluctuates between 15 and 18 mpg! Does anyone know what’s wrong with this car? This can’t be normal for a new model vehicle, even a V6.

1 Like

I seriously doubt there is anything wrong with the vehicle. If you are doing mostly city driving and it is winter time so the fuel usage will be lower than you expect. I assume you are checking the MPG the proper way. Also if you let your vehicle warm up in the morning that too will cause a lower reading. Have you checked it by pencil and paper on a highway trip at a reasonable speed ?

Edit: I guess I should mention that you do not have a V6 .

Are your tires at the proper pressure?

How are you figuring the fuel mileage and are you saying, highway, city, or a combination?

The EPA says 22 combined and any discrepancy could be easily due to a low tire or your foot.

I own a 2011 Outback with the same engine, which is actually an H-6. Subaru does not use any engines with a “V” configuration. But, to get to the point of the matter, I can tell you that my gas mileage with essentially the same vehicle is a consistent 23-24 mpg in local driving, except during periods of extreme cold, when my mileage can drop as low as 17-18 mpg.

That being said, if the Check Engine Light isn’t lit-up, then it is very unlikely that there is anything wrong with the car that could affect gas mileage. The most likely causes of poor gas mileage include the following:

Warming-up the engine for more than… maybe… 30 seconds before driving (Just drive conservatively until the engine is warmed-up)

Doing mostly short-trip, local driving (This is not good for the engine, or the battery, or the exhaust system, in addition to using a lot more gas.)

The way that you accelerate and brake (Learn to coast when you see a traffic light ahead turning red. Make believe that there is a raw egg between your foot and both of the pedals. The object is to press on the gas and the brake pedals so gently that you don’t break the egg’s shell.)

Not having your tires properly inflated (Do NOT rely on the car’s Tire Pressure Monitoring System. You need to manually check the tires with a hand-held gauge.)

Carrying excess weight around in the car (Some people carry things around that are not needed on a regular basis. Leave those excess items in your garage until you need to load them.)

Tailgating other cars. (People who tailgate have to hit the brake much more often, and then, after braking, they hit the gas again, thus ruining any chance at good gas mileage. Tailgaters use a lot more gas, as well as wearing out their brakes prematurely.)


a suv that gets 22mpg? how long have you owned it? done any longer trips? my suv gets 20 around town and 23 on the hwy. i was not expecting awesome mileage and it proved true. yes its empty. proper tire pressure. 2krpm at 60mph. i know any short trips during lunch time just kill the mileage. gotta stay put during the day

You obviously have a v4

The olds of a Subaru having a V-4 are zero. They’re all Boxer 4s or 6s.

Like OK4450 says , Zero chance of having a V4 engine . Also don’t see what that would have to do with terrible gas mileage .

You might want to check your tires and alignment. Some tires have much higher rolling resistance than others and a slight issue with alignment can cause a noticeable drop in fuel economy. I try to stick with tires that have lower rolling resistance and I have my alignment checked annually because I drive over 30,000 miles a year. With my snow tires on now I am getting about 30 to 31 mpg in my Mazda 6 with the 2.5 liter turbo engine (255 hp). My all season tires go on in a month and I expect to see a slight increase in mileage.

It appears that Carmen has left and why Patricia felt it necessary to post a wrong and vague comment is unknown .

Did you ever figure out what was wrong causing the huge drop in MPG. Same thing is happening right now with my 2017 3.6. No check engine lights, no changes as far as tires or fuel (always premium).

Jeff , Carmen only posted one time 2 years ago and it appears that her MPG was within range .

It will be best if you use the New Topic button and start your own thread . Give what MPG you were getting and what you are now getting .


Right there you could save money. That engine (I have the same one in my 2011 Outback) does not require premium gas and there is no real advantage to using premium gas in an engine that doesn’t require it.

Just for the sake of discussion, here are my typical mileage readings:
Around town in the warmer months: 24 mpg
Around town in the winter: 22 mpg
On the highway: 28 mpg
What type of gas mileage are you getting, currently?

Additionally, as was already suggested, you should begin your own thread, rather than tagging onto a dormant one.


I’m not concerned with saving a few dollars at the pump really. But, MPG has suddenly taken a huge hit. I would avg 22-23 mpg with mixed driving and 24-25 all highway.

Now - Highway trip a few days ago I saw 18-19 and just city driving <15.

Yes, but it just isn’t at all necessary to use premium gas. What benefit do you think you are deriving from it?

Anyway… when was the last time that you checked your tire pressures? Don’t rely on the vehicle’s TPMS, and instead, be sure to check them yourself, using a good-quality dial-type gauge. When I checked my tire pressures last month–after admittedly ignoring that task for too long–I found that they had all dropped by 4 psi. And, the TPMS warning light never came on.

Additionally, winter gasoline formulations will reduce your gas mileage:
Fuel Mileage Dropping? Blame The Winter Blend Gasoline (

And, if you have been warming-up the engine before driving, stop doing it, as it isn’t necessary.

1 Like

Maybe the premium fuel isn’t necessary, but it’s what I run and have always have - and I feel good about it :slight_smile:

There is no way tire pressure could cause a 30%+ reduction in mpg, that’s crazy. No warm ups, car always parked in garage

I think it was a crappy tank of fuel? Winter formulation or whatever maybe. I just went on a road trip to Vegas and fuel economy seems to have recovered. Avg’d 23 mpg at 90-95 mph, I can deal with that.

It was such a drastic drop in mpg I thought there just had to be something wrong with the car!

Thank you :slight_smile:

Good Grief , you spend money for premium fuel when it not needed . You logon to complain about poor MPG and you drive 90 MPH . How many other Goofy ideas do you have ?

1 Like

Guess you didn’t read that at all-

I didn’t complain one bit about my mpg at 90, I said it was GREAT at 23mpg!

It was awful when it was at 14-15.

I was scolded here once when I shared the story of my sister-in-law’s Avalon MPG going from 23 to 29 on a road trip after we stopped to get a tank of gas.
“Must have been going uphill”. “Must have been a headwind”.
“All the gas comes from the same refinery, so there can’t be differences”, etc.

Anyway, it might take a couple tanks of gas to confirm a fuel efficiency problem.

First thing that comes to mind is that the engine isn’t warming up properly.
Can’t trust the dash gauge.
They typically have a “dead zone”, where the needle stays in the same place over a range of temperature.
And the engine light won’t come on until it’s bad enough to increase emissions.
Easiest way to check is to connect an OBD scanner and see if the engine warms up to 180-190F (depends on the thermostat) before hot water goes to the radiator (feel the top hose).
A 2017 is pretty young to have a sticky thermostat, but anything can fail early.
It might be working well enough when the engine is working hard at 90mph, but not keeping the engine warm puttering around town.