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I had forgotten about the Average Speed favorite widget you can add to the display (I don't think it appears on any other fuel economy screen). This would be very helpful for people who are suffering from low fuel economy, especially in city driving. A lot of stop lights and idling can really bring this average speed down (and is indicative of a lousy environment for getting good economy).
 

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Be patient!

lve had my Ascent Touring f2 years. Gas mileage sucked for year 1. I was getting less than 20mpg. So disappointed!
Then it gradually got better. Now I average about 23.5 overall and about 25 on the highway. I also have a heavy foot, so I am pleased with what I’m getting and not having to drive at a snails pace.

We bought an Subaru Ascent Premium a few weeks ago and now have about 800 miles on it.

I've been driving it VERY gently -- accelerating slowly, not speeding, keeping RPMs low, paying attention to fuel economy meter as I drive, etc.

The best mileage I've ever gotten on a tank (according to the average MPG on the dashboard) is 20.4, and that was mostly long (60 min +) highway trips with no traffic.

We just refilled the tank after an average amount of city/highway driving. The dashboard said 17.2 for that trip, but we calculated 16.2.

We live in California, but in a normal suburban area (not city). It has been hot here, and I do run the A/C when I drive, but I don't think that should make this much of a difference, should it?

We did get a tow package with trailer brakes installed on our car a couple days after purchase, but we haven't been towing anything, so that shouldn't make much of a difference, should it?

I'm so upset about this, as I was sort of okay with getting low 20s for gas mileage, but I'm not okay with getting 16.2 mpg.

Is there anything the dealer can do?
 

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I had forgotten about the Average Speed favorite widget you can add to the display (I don't think it appears on any other fuel economy screen). This would be very helpful for people who are suffering from low fuel economy, especially in city driving. A lot of stop lights and idling can really bring this average speed down (and is indicative of a lousy environment for getting good economy).
The Average Speed favorite widget is now on my color display (together with Oil Temperature and the Accelerator Opening Ratio). My wife and I are getting slightly better than 18 mph in congested city driving -- the Average Speed widget shows 15 or 16 mph for the latest several tanks of gas. Sure it would be nice to get better mpg, but I still think that mileage is reasonable for an 8-passenger Ascent with great performance. I am finding the Accelerator Opening Ratio is also helpful to moderate my use of the accelerator pedal and to increase our mileage a little -- having been the previous owner of a manual transmission 2008 WRX, it still takes some restraint not to push down on the Ascent's gas pedal a little more forcefully whenever possible.
 
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The Average Speed favorite widget is now on my color display (together with Oil Temperature and the Accelerator Opening Ratio).
I'm going to add it to ours as well. I think it's a very useful metric to be able to report when talking about fuel economy. I've suggested to people before to do the hand calculations, completely forgetting that the car will do it for us.
 

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Just figured I'd add me own little anecdotal experience to the pile. I had to drive about 940 miles round trip from central Kentucky to the northern Illinois. Across that drive I averaged about 28 mpg, with an average speed of around 65.5 since we hit lots of construction areas. I generally sat around 5 over the speed limit for areas posted as below 70, and for areas where the limit was 70 I had cruise around 72. I drove both in areas that were very hilly (Kentucky) as well as some that were exceedingly flat (most of Illinois). Based solely on the data I got from my drive it is very obvious that the Ascent absolutely gets better mileage the closer you are to the speeds the EPA tests for mileage at. I put the 4 different legs of the drive I did into an excel spreadsheet and did the math for averages you'll see below. This drive was with approximately 500 lbs worth of people, and somewhere around 500 pounds worth of luggage/other random things we brought with us, including over 100 lbs worth of bottles of soda that my mother found for cheap and just couldn't pass up for the family event we were going to.
% of tripDistanceMileageAverage Speed
35.0568%​
330.2​
27.7​
67​
13.1755%​
124.1​
29.4​
64​
Drive there totals/averages
454.3​
28.16438​
66.18049747​
32.8803%​
309.7​
27.7​
66​
18.8874%​
177.9​
28.4​
63​
Return totals/averages
487.6​
27.95539​
64.90545529​
Whole Trip totals/averages
941.9​
28.05619​
65.52043741​

Obviously this is completely anecdotal but I've generally had very good experiences with my mileage thus far. I work downtown in my city and even then with downtown city driving to get to and from work I generally don't have much issue keeping my city mileage at 19-20. On the highway I also have generally seen my mileage sit right between 26-27 for my longer drives which is right where my Touring is rated for or slightly above. This trip was pretty interesting to see the mileage for since this is the first time I've exceeded the mileage ratings for a trip this long rather than just on short legs of a trip where I was basically driving downhill.

While there are certainly some people out there that are just having bad luck with their Ascents and truly not getting good mileage, I feel as though a large proportion of people just live with a lead foot and the Ascent is definitely one of those vehicles where once you starting breaking past 70 mileage starts to drop off pretty quickly it seems. I usually cruise somewhere around 5 over, but for this drive I really wanted to see what kind of mileage I would get if I sat right around 70 and surprise surprise I got better mileage than usual.

Side note: I have always liked driving so long drives have never bothered me, but man does having a vehicle with adaptive cruise control make them so, so much better. Adaptive cruise has to be one of my favorite features on my Ascent.

Pictures attached for validation/proof View attachment 13380
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Also forgot to mention, I like it cold so I had my AC running the entire trip set to like 68. And my Ascent is the dark gray magnetite and both days I drove it was clear skies and super sunny so it warms up quick in the sunlight without the AC running. I also have the Aero crossbars installed (but didn't have anything on them) so was slightly less aerodynamic than without.
 

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My understanding is that the fuel control system is calculating how much is being injected - over time it develops mpg by using this information and the odometer input.

It is not measuring by tank volume, correct?

Most of the quick read I just did indicates that lots of folks have compared their engines' management system computed MPG to their self computed, by tank, and the computed number is always better than the by volume used at the pump.
 

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I never understood the avg speed gauge. I would reset trip with a fresh tank, drive 70mph+ on the highway for hours, and it would show my average as being far less than 70mph.
 

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My understanding is that the fuel control system is calculating how much is being injected - over time it develops mpg by using this information and the odometer input.

It is not measuring by tank volume, correct?
Yes -- I'm 99% sure it measures fuel consumed using data from the fuel control system. It knows the total dwell (open) time for each of the fuel injectors since either trip meter was last reset and, likely combined with other metrics like fuel pressure, it knows how much fuel the engine should have consumed since the trip meter was last reset. If there is significant fuel consumption unbeknownst to the computer (a leaky injector, for instance), that could be a reason for repeated variances from the computer's calculation.

All that assumes, of course, that the computer's calculation is using correct logic, that there's not a bug in the software code, etc. I generally find that ours is pretty close. A manual calculation will never be very accurate on a single point (you can't be nearly sure enough exactly how much fuel was used based only on how much you think it took to get the tank full)...but recurring manual calculations that are significantly higher than the computer's estimate may indicate some type of leak.

I never understood the avg speed gauge. I would reset trip with a fresh tank, drive 70mph+ on the highway for hours, and it would show my average as being far less than 70mph.
It should be a simple distance driven per unit time calculation...while the engine is on and consuming fuel. So it counts all the time you've sat at the gas station at idle, all the time you may have idled the engine at a rest stop, etc. In theory, you should be able to reset one of the trip meters while in motion (say, at 70 mph using cruise control) and drive for X miles. Assuming you continue to drive 70 mph for X miles, that average speed meter should say 70 mph. I'll admit that I don't yet have it as one of my favorites. I'll try this very thing soon to confirm what I'd think it should be doing.
 

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The faster you go past around 55mph the worse the MPG.
I have to take a moment to laugh (respectfully) at the nearly-50-year-old information you're quoting there. 'Optimal fuel economy is achieved at 55mph' was the case in the days of carbuereted 6 and 8-cylinder Detroit (and Kenosha... a nod to poor AMC) Iron mated up to 3-speed automatics and 3- and 4- speed manual transmissions with approximately 1:1 final drive ratios. Since we have progressed to multi-port fuel injection, variable valve timing, computer controls, and most significantly, the fact that transmissions WITHOUT overdrive are now as rare as hen's teeth...

Times have changed.

Honestly, if anyone is still driving around at 55 in places where the speed limit is higher, you're probably not saving fuel, but you're likely causing traffic jams and accidents.
 

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I have to take a moment to laugh (respectfully) at the nearly-50-year-old information you're quoting there. 'Optimal fuel economy is achieved at 55mph' was the case in the days of carbuereted 6 and 8-cylinder Detroit (and Kenosha... a nod to poor AMC) Iron mated up to 3-speed automatics and 3- and 4- speed manual transmissions with approximately 1:1 final drive ratios. Since we have progressed to multi-port fuel injection, variable valve timing, computer controls, and most significantly, the fact that transmissions WITHOUT overdrive are now as rare as hen's teeth...

Times have changed.

Honestly, if anyone is still driving around at 55 in places where the speed limit is higher, you're probably not saving fuel, but you're likely causing traffic jams and accidents.
I think there is merit in both perspectives. Yes, fuel injection and CVTs and other modern technological advances have really improved fuel economy over the years, but the laws of aerodynamics, where wind resistance increases with the square of speed, still does apply. The faster you drive beyond the point where wind resistance becomes a significant factor (which is generally cited as about 35-45 mph I think), the more power you'll need to overcome the aerodynamics associated with that faster speed. In general, it still is true that more fuel is required the faster you go...though there probably isn't a hard break point at 55 mph (or any one speed).
 

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I have to take a moment to laugh (respectfully) at the nearly-50-year-old information you're quoting there. 'Optimal fuel economy is achieved at 55mph' was the case in the days of carbuereted 6 and 8-cylinder Detroit (and Kenosha... a nod to poor AMC) Iron mated up to 3-speed automatics and 3- and 4- speed manual transmissions with approximately 1:1 final drive ratios. Since we have progressed to multi-port fuel injection, variable valve timing, computer controls, and most significantly, the fact that transmissions WITHOUT overdrive are now as rare as hen's teeth...

Times have changed.

Honestly, if anyone is still driving around at 55 in places where the speed limit is higher, you're probably not saving fuel, but you're likely causing traffic jams and accidents.
This is true for the Ascent. Our best MPG has been around 55mph in Michigan upper peninsula.
 

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I have to take a moment to laugh (respectfully) at the nearly-50-year-old information you're quoting there. 'Optimal fuel economy is achieved at 55mph' was the case in the days of carbuereted 6 and 8-cylinder Detroit (and Kenosha... a nod to poor AMC) Iron mated up to 3-speed automatics and 3- and 4- speed manual transmissions with approximately 1:1 final drive ratios. Since we have progressed to multi-port fuel injection, variable valve timing, computer controls, and most significantly, the fact that transmissions WITHOUT overdrive are now as rare as hen's teeth...

Times have changed.

Honestly, if anyone is still driving around at 55 in places where the speed limit is higher, you're probably not saving fuel, but you're likely causing traffic jams and accidents.
Wow, it's not every day we get to see someone who is so confidently incorrect.

No one here is advocating for driving below the posted speed limit. Definitely don't do that when if you are going to be impeding the flow of traffic needlessly. But the "50 year old science" that you are mocking hasn't changed. Aerodynamics aren't suddenly no longer a thing. Yes we have generally more efficient vehicles than in the past and I'm sure that pure aerodynamic losses are more easily overcome with more powerful and more efficient vehicles, but the physics behind the fact that driving faster when you hit highway speeds is a simple statement of scientific truth.

As a matter of fact, 55 isn't even the correct value to state for optimal fuel economy in the majority of vehicles. According to the research done by Oak Ridge National Laboratory for the U.S. Department of Energy's Office of Energy Vehicle Technologies Office, in most situations economy starts to trend down after somewhere around 45 mph plus or minus 5.
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One really nice thing that we can notice here is that in every single test they did they had the same consistent result of fuel economy dropping when speeds reached greater than 55 mph, and were already on the way down before that speed was reached.

If you don't like the fact that they included data from Autonomie Vehicle System Simulation Tool, which I can understand as it is not real world hard data from actual vehicles, they also have tables without data that wasn't taken from actual vehicles being tested that we can use instead, and you know what you are absolutely correct that the data and statements regarding fuel economy declining after 55 are basically 50 years old. What you are completely wrong about is any statement regarding that no longer being true. Which we can see being proven again and again by tests over a period of 39 years, using 111 different vehicles.

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And per the U.S. Department of Energy Alternative Fuels Data Center the fact that it is less efficient to drive faster than 55 holds true not only for gasoline vehicles but also diesel and hybrids.
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The really nice thing about the research that Oak Ridge has done in regards to this is that it is all free to view and download yourself. Here is a link to their home page. I'm sure they would love to have more people peruse their work.

The only time I can see any data showing going faster than 55 resulting in better fuel economy was with testing done on Class 8 trucks (GVWR over 33000 lbs) and that comes with the massive disclaimer that the data has not been adjusted for terrain which is most likely what allowed for the trucks to gain increases in fuel economy because they achieved higher speeds when traveling down slopes. This is significant because the trucks were not just locked into a speed and set off to drive for a while, they were part of an actual companies fleet that were instrumented and had data collected over a year at 5 Hz for things like instant fuel rate, engine speed, vehicle speed, etc. This meant that a very large number of their data points for high speed readings would be while the trucks were driving downhill which would significantly increase overall mileage averages for data at those speed ranges. As such it is stated that it is not expected to actually be characteristic of all travel at those speeds.

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Hell, even something as simple as fueleconomy.gov tells us that driving faster than 55 reduces fuel economy.


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Now I'm not the hyper-mile obsessed guy who is gonna say you should stick to a 55 mph or whatever speed max for the most efficient drive possible. In fact I'm usually the one who yells at people on the highway who are driving below the speed limit from the safety of my car where no one can hear me venting. But don't jump into something acting ignorant and be condescending to those having a discussion when you apparently have no clue what you are talking about.

Please feel free to let us know about any other research or scientific data that we are not aware of, as something that important should definitely be forwarded to the U.S. Department of Energy if they really want to fight this climate crisis we find ourselves in.
 

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I was admittedly a tiny bit condescending in response to the condescension directed at my spouse in the original post. While I do NOT argue with your quoted statistics, I almost stand by my entire statement. I would just add saving "much" fuel. The fuel savings benefits are overshadowed by safety and general motorist sanity.

Honestly I have people in my greater circle of acquaintances that DO drive 50-55 no matter what, and that I find abhorrent.

My apologies for tone.
 

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I was admittedly a tiny bit condescending in response to the condescension directed at my spouse in the original post. While I do NOT argue with your quoted statistics, I almost stand by my entire statement. I would just add saving "much" fuel. The fuel savings benefits are overshadowed by safety and general motorist sanity.
I would agree with you that when it comes to overall improvements in safety of modern vehicles indeed overshadows vehicles of the past. However I also disagree with your change of phrasing to it not being "much" fuel savings. A 12.5% fuel economy loss on average (using the testing data using the vehicles from 2012) going from 50 to 60 in testing is already significant and going from 50 to 70 causing a loss of almost 25% on average in testing is absolutely substantial.

Honestly I have people in my greater circle of acquaintances that DO drive 50-55 no matter what, and that I find abhorrent.
I feel like you might benefit from finding some better acquaintances in this case. That is indeed insufferable on busy roadways. No one needs that kind of toxicity in their lives.
 

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Honestly I have people in my greater circle of acquaintances that DO drive 50-55 no matter what, and that I find abhorrent.
I feel like you might benefit from finding some better acquaintances in this case. That is indeed insufferable on busy roadways. No one needs that kind of toxicity in their lives.
Hopefully they at least have the decency to "slow lane(s)" and not clog the others! ;)
 

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Honestly I have people in my greater circle of acquaintances that DO drive 50-55 no matter what, and that I find abhorrent.
Alas, I'm one of the unfortunate people who live in an area where 50 mph and 55 mph are the highway speed limits (with 55 mph being the state speed limit). 😞

55 mph max for 150 miles of the island and parts of lower upstate NY...
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50 mph max on highways where it's signed that the speed limit is 50 mph. It's actually even less on some...
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And then there's this... five boroughs of NYC, and the max speed is 25 mph unless otherwise posted.
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Hopefully they at least have the decency to "slow lane(s)" and not clog the others! ;)
I don't know how it is in other areas, but, lately in my area, I've been seeing a ton of drivers in the middle and sometimes left lane who are doing the speed limit on the dot, and they're virtually always Uber drivers.
 

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I don't know how it is in other areas, but, lately in my area, I've been seeing a ton of drivers in the middle and sometimes left lane who are doing the speed limit on the dot, and they're virtually always Uber drivers.
Yeah, that's not uncommon here either (Bay Area/Silicon Valley). There used to be a lot of executive/town cars/limos around here that were really bad as well. A lot of them are super stubborn and don't like move over - it becomes really frustrating and dangerous when people start to weave in-and-out of traffic to get past them.

Don't get me wrong - I have no issue with people driving slow/slower, but just do it in the proper lane.
 

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I just wanted to weigh in on this MPG issue.

We have a 9-month-old 2020 Ascent Limited (in Canada) with about 13,000 Km (8,000 miles) and just came back from a week-long trip of roughly 2000 km (= 1250 miles). It was mostly highway driving (80%, I presume) and we got an overall (based on the vehicle computer) of 8.9 L/100 km (= 26.4 MPG). On the highway part only, driving at about 70 mph (the limit is 100 kph in Canada, but they "let you" go over by a bit), the fuel efficiency was up to 8.3 L/100 km (= 28.3 MPG). It was primarily the drive from Toronto to Quebec City; so mostly flat along lake Ontario and the St. Lawrence river and there were three of us in the car with our luggage. In comparison, on a regular week of mostly in-city driving, we get about 11.5 L/100 km (= 20.5 MPG).

Bottom line, we are happy with how hungry for gas the Ascent is. Definitely better than our old van it replaced and with definitely way more power and acceleration.
 

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28mpg in Canada is what, 24mpg in the US? ;)
It should be the same :D
It just hurts more on your pocket, as gas tends to be more expensive on this side of the border. I really miss the good-old-days when our $ was at par with the US $ and we could (first travel south and then) fill-up for less than half the price in Canada.
 
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