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2017 - Terrible Gas Mileage - 22.5 MPG Average?

12509 Views 59 Replies 42 Participants Last post by  Benny_Squach
I've owned my 2017 Fully Loaded Forester since 2017 (purchased new) when I was in Reno, NV. While I lived in Reno, the gas mileage was not good at all for general driving - I think I was getting on average 25mpg. I figured it was due to the high elevation.

Well, I now live in Bellingham, WA and I have roughly 22,500 miles on my car, and the average MPG is 22.5. I get this regardless of putting regular or premium unleaded in (tried 4 tanks in a row).

We have no extra weight in the car, and don't drive it crazy at all.

I'm appalled at this horrible gas mileage. The highest I've ever seen the car display is 28MPG when it was driven on the freeway for hours after a refill. I've never, ever broken 30MPG.

Is anyone else experiencing terrible MPG with their 2017 forester? Is this a problem due to the horizontal engine, or some other factor?

My car has been properly serviced since day one and the ECU reports no issues at all.

Honestly, if I knew the MPG was this bad, I never would have purchased the car.
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I lost 1-2mpg by going to a stickier tire vs OEM. But I love how they handle on grooved pavement so I rationalize it is safer and better on normal pavement. I also am disappointed by the fuel economy. I can pull the 32mpg on purpose, in hot weather, on a local red road. On the interstate? At practical speed? pfffft.

My advice it to use your onboard. Reset it once warm and moving. Observe the differences. You don’t have to drive crazy to reduce your mileage.
I bought a used '17 Forester Limited back in July, 24000 miles on it now. I get 32.1 everyday, 32.7 on trips. Put winter tires on last week, down to 30.5. I run 87 octane unleaded.
I have a 2015 Foz, haven't reset my mileage thingy for several years, drive 1/2 the time in the burbs and 1/2 the time on interstates and I am getting 22.3 MPG, regular gas. Using premium us just pouring your $ down the sewer.
@Requnix I have a 2011 Forester and recently noticed selecting trip meter A or B it then showed average fuel consumption, rather than ODOM where the value goes up and down.

Larger tire diameters make consumption seem higher because the care is calculating based on standard tire diameters.
However, I heard somewhere on a forum, or YouTube, that because the tires have a larger diameter you’re travelling further than the car thinks and that it balances out.
@Requnix try using Mobil 1 for cars over 75,000 miles and the proper grade shown on your engine oil fill thing. Mine is 5W-30. I got a 2-3 mpg boost with this oil.I actually got 25-26 mpg city, maybe 28 hiway.Does better under 60-63 mph. Lots worse over 70 mph. Headwinds are BAD, tailwinds are good. Keep tires inflated .A low pressure tire can kill your mpg. A clean engine air filter helps.
Sending this from Australia. I am surprised that your 'top tier' gas is 87.
1) "Top Tier" in the US is a designation created by fuel marketers indicating that the gas meets certain standards for detergency. It has nothing to do with octane; all grades of gasoline can meet Top Tier standards.

2) 87 Octane is the recommended fuel for non-turbo Foresters in the US.
@Requnix I live in Montana and bought a '17 Premium in June. Since then I have driven across Idaho and Nevada to CA and back. I set my top LCD in the Forester to the screen that monitors my overall and current mileage and I have been making observations on my mileage in relation to driving conditions.

I began doing this after observing mileage in the 25-26 mpg range while driving around 80 mph on the nearby interstate. On my summer trip, when I was on two lanes averaging a little over 65 mph, I could get mileage up to 33-34 mpg. (I was wondering if this is where Subaru got their window sticker epa mileage figures from). When on interstates with lower speed limits, I got 30-32 mpg driving around 74-76 mph. Back home in Montana, I discovered that if I set my cruise down around 76 mph while on the interstate (with our 80 mph speed limit), I could average over 30 mpg, sometimes up to 32. But with cruise back up at 80-83, I would be back down around 25/26 mpg. I also observed how hills and inclines could affect the mpg, but the biggest factor in my driving was wind. I live in a windy area. If I am driving 80 and the wind is strong, my mileage can plummet down to 22 mpg or even lower.

I wondered if the mileage computations the Forester is making are accurate, so, since I write down my miles and gallons when I fill up, I figured my actual mileage and found the onboard computer is about .3 to .8 mpg over the actual.

I have no idea why Requnix is experiencing such consistently lower mileage. With my '17, it seems to be all about the highway speed, incline, and wind conditions affecting my mileage. The OP needs to get some diagnostics done. Something isn't right.
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I purchased my 2015 new in 2014. At first, I was pleased with the fuel economy since I had driven a pickup for years. I was getting about 30 mpg highway, and 26 mpg around town. This continued for the first couple of years. I had a couple of long road trips during that time, and I was still working full time, so lots of town driving, too. Then the fuel economy began to decline. I have about 42000 miles on the car now and I'm getting about 18 mpg in town and 26 on the highway. I still live in the same place, my driving style hasn't changed except that I drive less now (retired). I still use the same grade fuel. I had the brakes redone this past spring, but that didn't have any effect. I purchased new tires in 2018 and that had no effect either. I'm disappointed with that aspect of the car, but I like it anyway and have no intention of getting rid of it. Has anyone else seen declining fuel economy?
I have a 2018 2.5i Limited CVT that is just about to hit 30k miles. According to the built-in MPG calculator my lifetime fuel economy is 33.6 mpg (see photo below). However, I do periodic manual calculations and usually come up about 1.5mpg less. Still, that's 32 mpg over the life of the vehicle. Granted, I do a lot of highway driving but much of it is at 65-79 mph. And I do a lot of mountain driving too. The 34.8 mpg in the display is since I last set trip meter B 1,314 miles ago. Needless to say I'm real happy with the fuel economy of my Forester. I always fill up with 87 octane Top-Tier fuel.
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I purchased my 2015 new in 2014. At first, I was pleased with the fuel ...
Has anyone else seen declining fuel economy?
If it is not drinking oil, I would consider a change of spark plugs.
My 2014 base model (CVT) gets 27-28 mpg in town stop and go, and around 33 at 60-65 on the highway. Driving faster drops the mileage pretty quickly.
I've owned my 2017 Fully Loaded Forester since 2017 (purchased new) when I was in Reno, NV. While I lived in Reno, the gas mileage was not good at all for general driving - I think I was getting on average 25mpg. I figured it was due to the high elevation.

Well, I now live in Bellingham, WA and I have roughly 22,500 miles on my car, and the average MPG is 22.5. I get this regardless of putting regular or premium unleaded in (tried 4 tanks in a row).

We have no extra weight in the car, and don't drive it crazy at all.

I'm appalled at this horrible gas mileage. The highest I've ever seen the car display is 28MPG when it was driven on the freeway for hours after a refill. I've never, ever broken 30MPG.

Is anyone else experiencing terrible MPG with their 2017 forester? Is this a problem due to the horizontal engine, or some other factor?

My car has been properly serviced since day one and the ECU reports no issues at all.

Honestly, if I knew the MPG was this bad, I never would have purchased the car.
Colder weather in Washington state than Nevada, perhaps. My 2017 Forester gets better gas mileage in the summer than in the winter here in Wisconsin
Got 41+ driving in YellowStone ( 2017 Forester) but the wife averages 26+ in city driving. I suspect either the gas you are using and/or tires and/or air pressure or some combo of those.

526036
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@Requnix
The Forester is an AWD car, which means there is extra running gear that runs all the time (Full time AWD)
It also depends a lot on your driving and driving conditions.
High speed = low mileage - Especially in a boxy SUV which is not very aerodynamic.
At speeds over 55-60 the mileage gets increasingly bad as the speed goes up due to drag. 2XSpeed=4XDrag
At 50-55 I can get over 30mpgs - At 80 I'm lucky to get much over 20.
Stop and go also plummets the mpg's as a lot of energy is used on getting the car up to speed.
If either of those apply, your mileage isn't far off the mark.
Pretending an egg is between your foot and the skinny pedal and keeping your tires properly inflated will help, but don't expect to get Hybrid Prius mileage, 'cause you won't.
Pretty much sums it up, I'm averaging 24-25mpg as per the lying gauge instrument cluster per tank, combined city/commute and freeway. On long road trips I've averaged anywhere from 22-33mpg depending on wind, roof top rack or box, level vs mountains etc.

IME 34psi in all four tires is best handling and mileage, Subi recommends 32psi which wears the tires edges more than the center and mpg suffers.

ALcohol/ethanol in the gas reduces mpg too, we have a blend all year and more ethanol percentage in winter months. I use 91 octane when available which is most the time, my 2010 would ping on anything less, 2015 not sure. There's different octane calculations too, RON or R+M/2 and a few others lol.

As was mentioned dirty air filters/oil, thicker oils will drop mpg too. ALso pointed out and something I've experienced is doesn't take much gas pedal pushing to decrease mpg.
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Resetting your trip meter while driving shows great mpg's on the guess-o-meter, but you seldom get anywhere near that over the life of the tank.
I can get get mileage rolling downhill too, but going up the hill on the other side.... Not so much..
;)
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I can get get mileage rolling downhill too, but going up the hill on the other side.... Not so much..
;)
LOL! That's fore sure. You can't count on those things.
An Expedition rental I had went negative while rolling downhill. I guess the digits rolled over.
Either that, or it realized how stupid the number was and gave up.
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Anecdotally, I noticed a distinct drop in gas mileage on my '19 Foz when I filled up a few times at Sam's Club.
When I switched back to Costco gas (and occasionally 76 or Chevron), the gas mileage went back to normal.
I have a base 2017 model and I get 28.5 MPG with my mix of city and freeway driving. This comes from a spreadsheet I use to calculate my mileage, gas consumption and cost of ownership, not the on-board computer.
When I do long freeway trips the on-board computer shows around 32 MPG for the trip. So I estimate that my city driving is getting ~24 MPG.
I have a '17 Forester XT with a turbo and I get 26-27 around town and 31-32 on freeways.
I have a 2015 Forester. My mileage dropped when I was forced to buy new tires. The OEM gave better mileage. My Michelin probably are safer. Mileage dies much above 70. At 65mph it is great. At 80 it is not. It was probably rated at 65mph. Great car but not perfect. Very happy with my first car I ever bought new. I have been buying cars since 1970.
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