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2012+ Subaru Impreza Real World Fuel Economy

139 messages,  Last post on Apr 26, 2013 at 10:05 AM

You are in the Subaru Impreza Forum.

What is this discussion about? Subaru Impreza, Subaru Impreza WRX STi, Gasoline, Fuel Efficiency (MPG), Sedan, Wagon

Messages Page 13 of 15

#116 of 139 Another disappointed customer by notsosubaru

Feb 24, 2013 (7:48 am)

My 2012 Impreza CVT hatchback gets between 22 and 25 MPG with just over 10,000 miles on the car to date. This is the first car I've owned that the actual gas mileage for my standard country and highway driving is less than the city MPG rating. If this was the advertised rating it would not have even made it to my final list.
 
It seems kind of coincidental that it wasn't on my list, primarily due to the MPG rating on the 2011, until the 2012 numbers were released. I've contact Subaru and my local dealer and so far have gotten canned answers. I'm curious, does anyone know if the testing standards have changed or given the automakers more room in reporting these numbers?

#117 of 139 Mileage Tips by clifm

Feb 24, 2013 (7:55 pm)

After 8500 mi and about a year of driving my Impreza manual hatchback, watching the mileage, calculating the mileage, and making notes, I have a few tips...
I just made a back-roads round trip from Chattanooga TN to Asheville NC and averaged right on 42 mpg for the trip (The display said 46 but real-world numbers corrected it down to 42), so I think I have figured out what works!
 
1. Tire inflation has been the largest single variable. The tires have a capacity of 51 psi but the dealership had only inflated to 32. Needless to say my first few tanks of gas didn't go far. Also the higher pressure tires seem to need topping off every month or so. I can drive around on a tank of gas with the tires at 35 and then inflate them to 45 for the next tank, and get 10% to 15% better mileage for the same type of trips.
2. Hills don't seem to make a difference, but out of habit I always slip out of gear going down. Staying in gear going downhill reduces mileage somewhat.
3. 45-55 mph seems ideal. Speeds over about 60 mph rapidly decrease efficiency.
4. Cold weather rapidly decreases efficiency, especially with short trips.
5. Oddly, running the AC in summer doesn't seem to be nearly as detrimental as driving in the cold winter air. That one surprised me.
6. Having the mileage display turned on actually results in getting better mileage; I probably am subconsciously adjusting my habits somewhat.
7. It doesn't seem like ethanol vs no-ethanol gas makes a difference. I have not tried anything other than 87octane, although I do notice some spark knock from time to time. In the coming months I may experiment with a mid-grade gasoline.
 
After taking these things into account I can usually average right on 30 mpg in mixed driving, 32-34 on 75 mph interstate driving in warm weather, and upwards of 40 mpg on long leisurely backroads trips. For cold weather (below 35F for us southerners!), everything takes a 5-10% hit.

#118 of 139 Re: Mileage Tips [clifm] by jd_24

Feb 26, 2013 (9:29 am)

Replying to: clifm (Feb 24, 2013 7:55 pm)
For the most part I'll agree with your post. I typically get 31 to 37mpg.
 
I'd lower the tire pressure a bit. The higher pressures will make for a harser ride and possibly less traction even on dry roads. Keep in mind the tires are fairly different from the base model to the sport limited. I do try to keep mine about 35psi on a Sport Premium, which is more than the recomended (31psi ??)
 
I'd add a number 8 and 9 to your list.
 
8. Length of drive/commute. 20+ miles helps. As you point out the cold weather makes a big difference. Any commute less than maybe 10 miles doesn't get to bring the average back up from the first 4 or 5 miles of a cold engine, and drive train. Even my old 2001 OB was the same way. The first 4 or 5 miles on a cold day 20F or colder, I bet it barely averages 20mpg.
 
9. Winter gas blends. Its not always more ethanol. In many cases its more butane that is added during the winter. 10% ethanol is required in many places year round. While ethanol is probably a factor, I think other additves in the winter blend have a bigger factor.

#119 of 139 Re: Mileage Tips [clifm] by once_for_all

Feb 26, 2013 (2:40 pm)

Replying to: clifm (Feb 24, 2013 7:55 pm)
45 psi (cold tire pressure) will trip a tire pressure light when the asphalt gets 100+. I really didn't notice any handling difference between 42 psi and 32 psi.
 
Mileage wise, simply keep the rpms below 2000, top speed below 65 mph, and take the foot off the gas well in advance of a stop. The car will maximize with those conditions.
 
John

#120 of 139 Re: 2012+ Subaru Impreza Real World Fuel Economy [2toroll] by kimpreza

Feb 27, 2013 (6:11 pm)

Replying to: 2toroll (Aug 05, 2012 4:06 pm)
I have a 2012 Impreza Hatchback that I love....EXCEPT for the MPG. I've had my car checked at the dealership for this and they brush it off on "winter mix" of fuel. I also drive only 1-2 miles to work and they say that also may be part of the issue.
Here is my MPG at present: 12.6!!!! This is a new tank of gas with about 40 miles on it. I also have reset both trips A and B, because the dealer said that I should do that as well.
I rarely have highway driving. Mostly all short spurts in city.
I've had my car since August, and did not have this kind of MPG then. It's been this winter.
I've also experienced a couple really hard starts that showed no computer codes when serviced.
I wish someone would come up with a solution.
Certainly is wrong of SUBARU to put the kind of MPG on the window sticker and commercials that they advertise when it is so NOT TRUE!

#121 of 139 Re: 2012+ Subaru Impreza Real World Fuel Economy [kimpreza] by tinycadon

Feb 28, 2013 (8:11 am)

Replying to: kimpreza (Feb 27, 2013 6:11 pm)
This "BRUSH OFF" is THE TRUTH!!! Do some research, you'll find it to be the case. Your 1-2 mile drive is a mpg KILLER as well. Your engine doesn't even have time to warm up to its normal operating temperature, so not only does this drive the mpgs down, then add in the winter mix gas and no highway driving + short spurt drives and yes, you should be getting 12mpgs! Here's a solution for your mpg problem, if it's only 1-2 miles to work, why not walk, or walk 2 or 3 times a week, it'll extend your time between fill ups so MPGs would no longer matter?

#122 of 139 Re: 2012+ Subaru Impreza Real World Fuel Economy [kimpreza] by jd_24

Feb 28, 2013 (10:38 am)

Replying to: kimpreza (Feb 27, 2013 6:11 pm)
Ouch! The 1 to 2 mile commute is the problem for sure. Over a year ago I read in the Toyota Prius Forum the somebody there had a similar issue. The Prius returned something like 22 mpg for their 4 mile commute. The commute was too short for the engine to warm-up and for the batteries to charge.
 
Subaru posts numbers on the sticker based on EPA tests. These tests are a standard that all manufacturer's are supposed to use. So unless Subaru faked the tests, they aren't lying about the MPG. Should the EPA have a wider range of tests? Certainly. Maybe 4 tests like "short trip", "city", "highway", "highspeed". That way they would fit a wider range of driving styles.

#123 of 139 Re: 2012+ Subaru Impreza Real World Fuel Economy [jd_24] by oxmead

Feb 28, 2013 (4:50 pm)

Replying to: jd_24 (Feb 28, 2013 10:38 am)
I just returned from a 2200 mile road trip, and the Impreza IS capable of the epa numbers and more. The 950 mile return trip got a 41.4 average readout ( 39 actual) Trick is you have to keep it at 60 or under! The temp was mid 30's and no high winds. Conditions were mostly flat but rain and light snow.
 
PS, I also did some awd driving in 8 inghes of snow in a Target parking lot and had a blast!

#124 of 139 Re: 2012+ Subaru Impreza Real World Fuel Economy [oxmead] by once_for_all

Mar 01, 2013 (12:08 pm)

Replying to: oxmead (Feb 28, 2013 4:50 pm)
hmmm...watch that 8" of "snow plowing" with the front spoiler. You'll get some body damage that way.
 
John

#125 of 139 Re: 2012+ Subaru Impreza Real World Fuel Economy [once_for_all] by runnerdog1

Mar 02, 2013 (7:14 am)

Replying to: once_for_all (Mar 01, 2013 12:08 pm)
Yeah, I got my first body damage on my 2012 Impreza when the corner of the front bumper hit a snow drift that was a little taller (and harder) than I thought as I was making a right turn. Crunched the underside on that corner, but its not that obvious. The Impreza is not a very good snow plow. Handles well on ice and in the snow, though, so long as the snow isn't too deep. Glad to know the EPA rating is possible. Perhaps my abysmal numbers will start to get better as I get more miles on it and warm weather returns. I'm not driving below the speed limit though. The on-road travel I do is mostly long hauls and I don't want to make them any longer.

Messages Page 13 of 15

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