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What's Your MPG Averaging?

43K views 179 replies 84 participants last post by  HeyChris 
#1 ·
I've had my Ascent for a few weeks now and am averaging around 18-19 MPG. I thought it would be better though I am doing mostly city driving. What's everyone else's average MPG?
 
#8 ·
I'm just hitting an average of 23mpg, and still slowly increasing. I am at 2300 miles so far. Give it 5,000 miles or so...
 
#9 ·
Just a question. Are you all basing your MPG based upon the car's computer system or are you putting pen to paper and doing the hard math? If you are not doing the hard math, it may be worth trying. If you are seeing something different when you take your trip miles and divide it by your gallons to fill than what the computer is reading, it simply could be something with the calibration in the system. Now if you put paper to pen and are actually getting teens, the question becomes Why? I am not sure why, but about every 3-4 fills, I run manual numbers to compare against my cars trip calculations.
 
#23 · (Edited)
The caveman side of my brain does enjoy feeling the turbo kick in.

As far as MPG, I'm around 17 by way of the trip computer but I'm still under 200 miles total and only on my second tank so I expect that to improve. If you want to compare your car info to the real world, download a speedometer app. It uses GPS and is arguably more accurate than a speedo anyway. Mile markers are all but useless and should only be used for general navigation purposes. I used to drive for a living and would do all sorts of things to keep from being bored. I used my old dash mounted GPS against the car and the sign posts over a 350 mile trip. In the end, the car and the GPS agreed with each other within half a mile and the signs were off by 6 (yes 6) miles. Sign installers do the math but still have to find the best spot to place a sign.

The MPG average is really just an estimate. Miles driven divided by estimated consumption. In most, if not all, cars it isn't measuring actual fuel flow per se. They measure how long the fuel injectors are open and at what duty cycle. It's measuring against an assumed chart of performance. In other words, it compares your driving habits against a chart and says "Here is what the chart says your MPG should be under those conditions". If your fuel pump happens to work at slightly higher or lower pressure than "normal" the calculation will be off a bit.

It'll get better at it as time goes by but will never be as good as the hard math. The car just can't account for every conceivable parameter that affects gas mileage. Even the brand of gas makes a difference. For a long time I only used FINA gas because it consistently gave 4 to 5 higher MPG than the other brands. Then it became crap and clogged my fuel filter every 4k miles or so.
 
#25 ·
The caveman side of my brain does enjoy feeling the turbo kick in.
And that's where I destroy my mpg. :sad:

I do soooo well for a while, and watch my mpg creep up... and then, I go on binges of making the car really move. Sigh. :plain: :smile_big: :grin:
 
#30 ·
I've gassed up four times so far, and averaged:

19.77mpg (city driving)
22.34mpg (all highway)
24.77mpg (some gravel roads, but mostly rural—think two lane roads w/o many traffic lights and 55mph speed limits)
26.14mpg (almost all highway driving, some city.)

That last fill up was especially cool—I drove 353 miles total, but 280 of them were highway driving. When I got off the highway, the car was telling me that I'd been averaging 28.9mpg for the duration! It dropped precipitously over that last 73 miles of city driving, though.

And this is on a Limited with 2 adults + 2 kids in it, lots of luggage (we had one of the rear seats folded down), the AC on, and 4 devices plugged into the USB ports. And I still got 28.9 mpg! Well, at least according to what the car calculated. The mileages I posted above are what I calculated after I gassed up.

I was using a lot of pulse-and-glide hypermile techniques. So I'd get the car to the speed I want or a smidge over and let off the acceleration momentarily, then put my foot on the gas to basically hold the speed. The computer was very happy with that and my mileage shot up a lot. As best as I can tell from my calculations, it was pretty accurate.

The car seems to have a sweet spot between 45-65mph where it looks like it'd happily hold 30mpg w/o much issue (assuming level roads, minimal accelerating, etc). Mileage drops off quite a bit around 80mph, which is why my highway driving going on vacation was worse than my highway driving coming back. ON the way up I was averaging closer to 80mph, on the way back was more like 70mph.

I was able to pulse and glide to get better gas mileage than the cruise control did.

It's still really new, of course, I'm only at about 1350 miles total. But it looks like a car that you can squeak out superior mileage from if you actively monitor your driving on it. I've been very happy!
 
#33 ·
Filled up again yesterday. About 60/40 highway vs city using costco gasoline.

Trip computer: 24.1 mpg
Calculating by hand: 23.87 (16.534 gallons delivered 394.8 miles)

Slowly getting better which is nice.

First tank: 19.1 (80/20 highway/city)
Second tank: 19.1 (50/50 highway/city)
Third Tank: 23.87 (60/40 highway/city)
 
#36 ·
2000 miles on my wonderful Crimson Red Ascent Limited so far. Each tank of gas has gotten lower in avg mpg. I attribute this mostly to driving mix and conditions. What it has shown me, is that this vehicle is somewhat sensitive to use. Like a previous poster, I have had vehicles with large V8's that didn't seem to care how they were driven. They sucked gas the same regardless. This Ascent appears to reward good driving and good driving conditions. I'll have to work on that. I have seen average for a tank at 26.8 and also at 19.0. I'm a 1/4 into the current tank and am only up to 17.
 
#37 ·
My Crimson Red Touring went over 2000 on my recent trip to Canada. All highway driving on interstate at 70 - 78 mph, 23.1 mpg on the screen. Driving in Canada at their speed limits of 40 - 60 mph, 27.1 mpg. Now driving around town with a few highway miles, 19.1.


This vehicle is capable of getting stated mileage, but it takes lower constant speeds with a light foot.
 
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#38 ·
What kind of mileage are people getting, who are calculating ACTUAL mileage? (IOW, not using the trip computer)

Example: My trip computer calculated my first tank of gas at 24mpg. Real life, I traveled 352.1 miles on 15.9 gallons of gas... for a true mileage of 22.1mpg.

I'm not saying what I got was good, bad or indifferent... and not blaming Subaru, all cars seem to have this issue... just stating the fact that there can be quite a difference between what the car wants you to think you are getting, and what you are actually getting.
 
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#40 ·
Filled up today. Trip computer showed 21.4 mpg. Calculating by hand shows 20.76 mpg (13.653 gallons delivered 283.5 Miles). This tank was 50% city and 50% highway.

My mileage so far:

First tank: 19.1 (80/20 highway/city)
Second tank: 19.1 (50/50 highway/city)
Third Tank: 23.87 (60/40 highway/city)
Forth tank: 20.76 (50/50 highway/city)

Temps were between 60 and 90. Mostly flat. Trips under 15 miles each. Anecdotally it felt like I hit more red lights than usual on this tank.
 
#44 ·
Did you set the fuel tank size in Fuelio to 19.3 gallons?

Also, are your tire pressures correct?

How much is stop and go traffic?

Whats the computer saying in terms of MPG?


Does the Ascent have an "eco mode"? I have not seen it?
It does not.
 
#42 ·
The mpg seems to vary greatly with different driving conditions. When taking it easy on the throttle & a mix of driving mine falls around 24mpg. If I have a lot of stop & go rush hour traffic it will drop down to 20mpg. A road trip with 60-65mph speeds had a tank above 26mpg. I have recently set the cruise control acceleration to 1 step above eco & use it everywhere possible, since doing this it has been consistently above 24mpg.
 
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