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2014 Subaru Forester XT CVT
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Discussion Starter · #1 ·
Have a 2014 XT with about 7500 miles on it in Wisconsin. Been getting 26-27 MPG average with about 50/50 highway/city miles when I am light on the accelerator. In the past month I have seen my average drop to 22-23 using the exact same driving methods over the same routes.

I realize that the colder weather and winter blend fuel will have an impact but a 15% reduction? What's going to happen when the *real* cold weather hits? It's only been in 30-50 degree range this past month - I can only imagine what 10 degrees will be like.

I run 91 octane with no ethanol. I am coming from a Nissan Murano with a CVT that only saw about a 7% decrease in winter MPG... Is this just the accepted norm with XTs?
 

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2014 Forester XT Touring CVT
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12,775 Posts
The winter blend fuel was probably close to 10% of your drop.

The other 5% you have seen is probably from the engine taking longer to warm up. The torque converter is not locking up (to warm the engine quicker) causing you to run higher RPMs when driving on a cold engine, yielding a drop in economy that will be quite noticeable if you make shorter trips.

If you are not driving on a cold engine and let the car warm up idling, you are just burning fuel that way too.

Threads on this topic:

http://www.subaruforester.org/vbulletin/f88/xt-mpg-decreased-245098/
http://www.subaruforester.org/vbulletin/f107/mpg-winter-blend-questions-245474/
http://www.subaruforester.org/vbull...ge-does-your-forester-get-118680/index13.html
http://www.subaruforester.org/vbulletin/f107/real-world-mpg-14-fxt-2-0-a-135745/index9.html
 

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2014 Subaru Forester XT CVT
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27 Posts
Discussion Starter · #3 ·
The winter blend fuel was probably close to 10% of your drop.

The other 5% you have seen is probably from the engine taking longer to warm up. The torque converter is not locking up (to warm the engine quicker) causing you to run higher RPMs when driving on a cold engine, yielding a drop in economy that will be quite noticeable if you make shorter trips.

If you are not driving on a cold engine and let the car warm up idling, you are just burning fuel that way too.

Threads on this topic:

http://www.subaruforester.org/vbulletin/f88/xt-mpg-decreased-245098/
http://www.subaruforester.org/vbulletin/f107/mpg-winter-blend-questions-245474/
http://www.subaruforester.org/vbull...ge-does-your-forester-get-118680/index13.html
http://www.subaruforester.org/vbulletin/f107/real-world-mpg-14-fxt-2-0-a-135745/index9.html
Thanks for the response, I appreciate it. I do notice that the engine is running at higher RPMs at startup, which explains the extra loss. I just wanted to make sure it was normal and that there wasn't something wrong.
 

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2015 Highlander AWD XLE 6AT
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4,255 Posts
I'd put the fuel economy drop caused by the winter fuel blend at ~2%.

Other factors include:

1) Increased aerodynamic drag due to higher air density (colder air + lower humidity)
2) Longer engine warm up period before emissions controls kick in
3) Reduced tire pressure due to lower ambient temperature. Figure on a one psi drop for every 10 F drop in ambient temperature
4) Higher electrical loads (lights, electrical defrosters, a/c defroster for windshield, seat heaters, etc.)

Note that turning on the windshield defroster when ambient temperatures are above 32F will activate the a/c compressor to help with air drying and defrosting. Other than increased engine load, there's no indication (i.e., lamp) that the a/c compressor has been activated.

HTH,
Jim / crewzer
 

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2018 Forester 2.5iLimited CVT
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256 Posts
Yeah, I don't think it is primarily due to winter blend. Today it was in the low 20's here and my mileage dropped about the same without a change in the fuel in the tank. It is the cold weather and effects associated with that, IMO.
 

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2014 Forester manual
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11 Posts
I'm experiencing the same thing, I was averaging around 32 mpg, now it's just under 30. My 2004 Forester also had about a 10% - 15% drop in winter. I guess its just normal.
 

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2014 Forester 2.5 Premium CVT
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25 Posts
Every car is going to take a hit on MPG in cold weather for the reasons everyone's already posted, it's just more noticeable now that you have a dozen different charts and graphs telling you.
 

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2019 Crosstrek 2018 Forester XT
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15,021 Posts
I drop around 2 mpg in winter with my 08X
 

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2015 Highlander AWD XLE 6AT
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4,255 Posts
Here are some examples of the vagrancies of winter weather. I snapped the first two pics last Sunday afternoon driving from western NC to central KY via TN. Weather was relatively warm, the air was humid, and there was a gentle wind from the south. Gas was 87 AKI "winter" blend.





The next pics were taken on Monday, while driving from central KY, across IN, and then to northern IL via Bloomington. Weather was much cooler, much drier, and I was headed into a stiff headwind, which got worse as the day progressed. Gas was still 87 AKI "winter" blend, some of it left over from the day before.





Our Forester did fine on winter gas while running in warm, humid air with a bit of a tailwind. With a fairly high Cd, and therefore a high drag area, running into a cold, dry, stiff winter headwind was another story. 32 mpg to 24 mpg (both indicated) represents a 25% drop in fuel economy. :icon_cry:

HTH,
Jim / crewzer
 

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2011 2.5X Premium, AWP 5MT
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566 Posts
I did a road trip last week from San Jose out to Vegas then over to Northern Arizona and Southern Utah and back again. Lost count of how many summits I went over. Anyway, I was pretty happy with MPG on the way out there in the 29 mpg range even doing 75 - 85 MPH (gotta love Utah and their 80MPH speed limits). However on the way back Saturday (I drove from Canyonlands Natl Park to San Jose in 1 day .... 1000 miles - ouch!) there were some strong winds. 14MPH average with 38MPH gusts. Sometimes cross, sometimes head. MPG was no better than 26 no matter how I tried to take advantage of downhills etc. Temps were about 10deg colder on the way back. Wind is a killer. I haven't tallied the overall trip MPG yet but I'm guessing in the 27-28 MPG range overall.
BTW, I was filling up with 85 AKI in Utah and Nevada, they had 85, 87 and 91 available. In Cali I'm using 87 (only 87 and 91 available here). That might have accounted for some of the difference going out (Mostly 87AKI) vs coming back (85AKI).
 

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2014 Forester Ltd. CVT
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1,779 Posts
I was getting reliably 32 mpg going up to seattle; with the cold snap (and maybe fuel remix--who knows when the shift happened?) dropped to 29.1. :-( But still better than my old SH :)
 
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