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As the title suggests, I did my first road trip yesterday and noted some interesting things. I only averaged 26.7 MPG (computer said 26.4). When I first started (around 60 to 65 MPH), the computer was reporting 29.1 MPG. When I started encountering mild hills, the number dropped to 28.2. Then, when I hit the 70 MPH zone (most of the trip), it steadily fell until I arrived at home. I was expecting a little better mileage. Is this close to what others are getting?

The other thing I noticed is that the speedometer reads anywhere from 2 to 4 miles per hour fast. This means that I wasn't actually driving 75 MPH in that 70 zone. More like 71. I've had numerous cars that did not have accurate speedometers, but none of them were off by more than 2 MPH. After calculating mileage, I discovered that both front tires were 4 lbs low, so that may have been a factor. On the plus side, while filling my tires, I discovered that that car has all new brakes (rotors still have hash marks).
 

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2012 OB 2.5i. Approximately 75,000 miles. Purchased used 11/29/19
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Where are you located? I am in Wisconsin and the winter bkend fuels really reduce mileage.

I have 2012 and nust bought it right after thanksgiving. I took a trip and most was at speedometer of 77 mph and averages by cars computer 24.6 mpg on a 2.5 liter engine.

This was also disappointing to me.

Another coworker who has owned several Subaru s said that the cold wearher and winter blend fuels resuce his mislage every year by about 20%. More than any other car brands he has ever owned before.

I did notixe last warm soell where we has 55 degrees, I did get noticeably better gas mileage. Even at 62 mphI was then getting like 27 mpg.

Why the car would be so sensitive to outside air temp is beyond me!
 

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After driving around town a week, I get about 24.5... i drive 60 mins by freeway to work each day..
I have a 2013

If I reset the mpg while on the freeway, it hovers around 35-40 mpg till I have to accelerate or get off the freeway...

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2013 3.6R limited. 2006 Wrx Limited
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As the title suggests, I did my first road trip yesterday and noted some interesting things. I only averaged 26.7 MPG (computer said 26.4). When I first started (around 60 to 65 MPH), the computer was reporting 29.1 MPG. When I started encountering mild hills, the number dropped to 28.2. Then, when I hit the 70 MPH zone (most of the trip), it steadily fell until I arrived at home. I was expecting a little better mileage. Is this close to what others are getting?

The other thing I noticed is that the speedometer reads anywhere from 2 to 4 miles per hour fast. This means that I wasn't actually driving 75 MPH in that 70 zone. More like 71. I've had numerous cars that did not have accurate speedometers, but none of them were off by more than 2 MPH. After calculating mileage, I discovered that both front tires were 4 lbs low, so that may have been a factor. On the plus side, while filling my tires, I discovered that that car has all new brakes (rotors still have hash marks).
I find the computer numbers to be inaccurate. I track mileage at every fill up.

I'm convinced the speedo being off is by design.
 

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2012 OB 2.5i. Approximately 75,000 miles. Purchased used 11/29/19
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My phone gps app for speed matches about exactly with my cars speedometer. It also matches garmin GPS.

I will have to compare computer to actual math of gallons and miles. But if the speedometer is off the odometer is probably off. So the calculation won’t be accurate either.
 

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Discussion Starter #6
Where are you located? I am in Wisconsin and the winter bkend fuels really reduce mileage.

I have 2012 and nust bought it right after thanksgiving. I took a trip and most was at speedometer of 77 mph and averages by cars computer 24.6 mpg on a 2.5 liter engine.

This was also disappointing to me.

Another coworker who has owned several Subaru s said that the cold wearher and winter blend fuels resuce his mislage every year by about 20%. More than any other car brands he has ever owned before.

I did notixe last warm soell where we has 55 degrees, I did get noticeably better gas mileage. Even at 62 mphI was then getting like 27 mpg.

Why the car would be so sensitive to outside air temp is beyond me!
I'm in eastern Washington state, but I filled up in Portland, OR. Not sure at what temperature they start winter blended fuel, but temperatures have been well above average in the pacific NW this year. I only fill up with Chevron regular, and it usually shows with better mileage and a cleaner engine. Some posts on other threads suggest that cars get worse mileage at lower elevations. If this is true then it would also make sense that colder air would result in lower mileage. Cold air is denser, and so is air at lower elevations. However, I have always thought that denser air was better (hence the reason people install cold air intakes).

On my trip, I went from about 250' above sea level to about 2,600', and most of the drive has lots of steep hills. I was carrying about 500 lbs of tools and other stuff, so this trip might not be a very good example of what to expect.
 

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1. Speedo is going to read fast, that is by design.

what drive train are you using?

an outback will get slightly less mpg than the legacy due to it being higher off of the ground. I have a calculated average of 21mpg mixed right now with a 2010 Outback 3.6R
 

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Discussion Starter #8
1. Speedo is going to read fast, that is by design.

what drive train are you using?

an outback will get slightly less mpg than the legacy due to it being higher off of the ground. I have a calculated average of 21mpg mixed right now with a 2010 Outback 3.6R
I have the CVT. It makes sense that a higher profile car would get worse mileage, but my parents' 2015 Forester gets about 32 MPG on the highway. It's even taller than the outback. Of course, their CVT has some improvements over my 2013.
 

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OP, your numbers are nearly identical to what I get.
At 65mph, the computer will rack up 29mpg.
At 75+mph, the computer will drop down to 26.5mpg.
Cruise control is not as fuel efficient as I can be as I'll let the speed drop a couple of mph when cresting overpasses and small hills.
My speedometer reads too fast as well by a few mph but the odometer is accurate. It is not unusual for manufacturers to set their speedometers optimistic.
 

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Discussion Starter #10
OP, your numbers are nearly identical to what I get.
At 65mph, the computer will rack up 29mpg.
At 75+mph, the computer will drop down to 26.5mpg.
Cruise control is not as fuel efficient as I can be as I'll let the speed drop a couple of mph when cresting overpasses and small hills.
My speedometer reads too fast as well by a few mph but the odometer is accurate. It is not unusual for manufacturers to set their speedometers optimistic.
You drive the same way I do. Contrary to popular belief, cruise control is not the most fuel-efficient way to drive. I always take advantage of fuel shutoff on downhill slopes, and assuming that hills are not very steep, I just keep the throttle where it was and accept the slower speed for a bit. How are you sure that the odometer is accurate? I think the speedometer and odometer use the same sensors.
 

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Neither of my Subies return very good MPG in cold ambient temperatures. Also, the winter-blend fuel hurts and so does ethanol (alcohol) in the fuel.

If you are looking for the very best MPG on a long trip, fill up with NONethanal fuel and drive in warm ambient temperature. (also, locking the cruze control at 53MPH...but not many folks have the patience for this.)
 

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How are you sure that the odometer is accurate? I think the speedometer and odometer use the same sensors.
Even if they do use the same sensor the odometer only needs the number of pulses whereas the speedometer uses the rate and translates that to an indicated speed. The manufacturer can calibrate that to almost any display speed desired via software. This is how some dashboards can switch between mph and kph.
Next road trip, you can compare your odometer to the mile markers. Average it over several miles for best results.
 

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What’s your tire size? If tires happened to be replaced with an incorrect size could effect your speedo reading.


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Discussion Starter #14
Tires are stock size (225/60R17), but I recently discovered that the base model OB uses 215/70R16. Base model tires are a larger diameter than those that are equipped on the Limited. I wonder if Subaru decided to base all speedometers on the largest tire diameter, so most of them read fast.
 

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I have the CVT. It makes sense that a higher profile car would get worse mileage, but my parents' 2015 Forester gets about 32 MPG on the highway. It's even taller than the outback. Of course, their CVT has some improvements over my 2013.
Forrester is a lighter vehicle and the gearing may be different in that car, tires, engine makes slightly less power.... (170 vs 173)
 

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Hmmmm, Yesterday I had a good hiway stretch with my 3.6. 20 miles from the Fl. State line to Orlando with the cruise set @ 72(which is best I can tell 70) My computer was showing 29.1 when I parked. My computer is always 1.3 MPG high on trips like that. So that is around 27.8 MPG...much better than the EPA rated 25 MPG!
 

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Where are you located? I am in Wisconsin and the winter bkend fuels really reduce mileage.

I have 2012 and nust bought it right after thanksgiving. I took a trip and most was at speedometer of 77 mph and averages by cars computer 24.6 mpg on a 2.5 liter engine.

This was also disappointing to me.

Another coworker who has owned several Subaru s said that the cold wearher and winter blend fuels resuce his mislage every year by about 20%. More than any other car brands he has ever owned before.

I did notixe last warm soell where we has 55 degrees, I did get noticeably better gas mileage. Even at 62 mphI was then getting like 27 mpg.

Why the car would be so sensitive to outside air temp is beyond me!

I am also in WI and notice that mine goes down significantly in the winter starting around November and going until April/May. During the summer I am usually high 20's or low 30's winter is solid 24-26
 

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2012 OB 2.5i. Approximately 75,000 miles. Purchased used 11/29/19
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Last night. 77mph on It was windy. Temp about 30 degrees. On level, the computer instant mpg never was above about 21 mpg. This is 2012 with 2.5 liter 4 cylinder.

That just seems too low from what everyone else seems to report.

The next fill up of gas, I will compare average mog from Computer and compare to the math of total miles divided by gallons to refill at the same gas station.

I nist dont know why ot is so low. All cars in the past I woild beat the EPA Numbers. This subaru I am not even close.
 

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Discussion Starter #20
Update
I took my OB on a road trip to pick up some Legacy rims I found on CL, for mounting snow tires. Total distance was about 170 miles, and I averaged about 63 MPH the whole way except for 15 miles in stop and go traffic. Computer indicates round trip mileage at 30.3 MPH, but that isn't the whole story. My travel was north and south, but there was a strong WSW wind at around 30 MPH with gusts over 40. Mileage going north was 33 MPG, so going partially against the wind going south must have cut my efficiency significantly

Lots of factors involved between my first trip and the one I took today. Both were hilly with long grades. Overall elevation on my first trip went up 2,350 feet while the second trip was roughly equal. Front tires had 4 more PSI of pressure on second trip. I now have used two tanks of good Chevron gas instead of whatever the previous owners were using. My average speed on the first trip was around 72 MPH and 63 on the second trip. I can't say for sure what factors played a role, but 26.4 to 30.3 MPG (according to computer) is a significant improvement.
 
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