Subaru Ascent Forum banner

Gas Mileage Realities And Tips... post your tips on HOW TO get good gas mileage

9924 Views 43 Replies 22 Participants Last post by  DAC17
Post your tips on HOW TO get good gas mileage - my experiences and tips are below:
This thread isn't about "gee, I got horrible gas mileage" - this thread is to assist those who are getting bad gas mileage with tips from those of us who are getting good gas mileage, so, hopefully, you can do the same.

I just did 281.6 miles, and got 27.4 mpg (27.3 mpg by the time I let the car idle while taking the photo below). And that's on my heavy BF Goodrich All Terrain T/A KO2 LT tires.

Motor vehicle Automotive lighting Font Parallel Technology

Toughest thing is, people don't realize that EPA Highway Fuel Economy testing is 60 mph and less (this is the EPA's tests, not Subaru's). Even so, careful use of the accelerator (as little use of it as possible other than to hold speed) can result in great MPG.
Rectangle Product Azure Slope Plot

Even though 2/3 of my trip was 70 mph (everything to NYC), and the rest was between 50-60 mph (NYC to my home exit) followed by 3 miles at 47mph, I still managed to beat EPA ratings. I was fully in "automatic" mode the entire way (no manual shifting, even though the mountains), with ACC in Adaptive mode. I did remove my roof rack for this trip (they eat gas mileage).

Things against me:
  • Very heavy BF Goodrich All Terrain T/A KO2 Light Truck tires (five of them, counting the hitch mounted spare).
  • COBB AccessPort running 93 octane tune
  • Hundreds of pounds of gear
  • Drove through the Adirondack High Peaks Region, and made some stops (such as the photo stop for the photo I posted earlier).
  • Drove through the Catskill Mountains.
  • ⅔ of my trip was at 70 mph

So, remember, it's not that the fuel ratings of the car are wrong. They are not. If you live in Utah, you will probably never make EPA ratings, because the speed limit is 20 mph OVER the EPA's Highway test ratings' maximum speed.
Speedometer Odometer Trip computer Motor vehicle Light

If you live somewhere where you can keep the speeds at 70 mph or below, and not keep changing speeds (as traffic sometimes requires), most of you CAN make EPA ratings, especially because most of you are not running tires as heavy as mine. A friend made a nice little graph of what speeds gas mileage really starts to suffer.
Rectangle Slope Plot Font Parallel

When I am enjoying using my turbo, my highway gas mileage is only 21-23 mpg. Adjusting my driving habits netted me Almost 4.5-6.5 mpg better.

  • ACC isn't magic. Key factors involved is what the traffic in front of you is doing. If your cruise is set at 70 mph, and your Ascent has to keep slowing to 50 and then speeding back up, you will be eating gas. To get great gas mileages, I try to drive at as steady of a speed as possible.
  • The Ascent has a turbo, with a quick tip-in point. Unless you learn your throttle, you're going to be burning gas.
  • It's fun to floor the Ascent, but, don't do it and expect good gas mileage.
  • MOST OF YOU live in areas where the speed limit is 65, 70, 75 or higher. If you're driving over 70 mph, you will rarely, if ever, see EPA highway ratings, because the speed for the testing is 60 mph or less.
  • NO, Subaru can't just make up their own tests. Car manufacturers follow the EPA testing, as they are required to.
  • The Ascent has a massive and flat front end, as required to suck in all the air the turbo needs and to keep engine and CVT cool - so, yeah, making gas mileage ratings may have been easier on your previous, smaller, turbo vehicle. The Ascent is a big 7/8 passenger car.

Maybe EPA Highway Testing speeds need to be updated.

Instead, they added a "High Speed" test, but that's not the data on the EPA Required "City/Combined/Highway" posts/stickers.
So, until things change, I guess it's a matter of being realistic with our expectations. Next time I go cross country, I know I can't make EPA ratings, because I will be traveling considerably faster than the 60 mph speeds that the EPA requires for testing highway gas mileage.
See less See more
  • Like
Reactions: 3
41 - 44 of 44 Posts
running stop signs, etc, all have no bearing on the Ascent's MPG.
Running stop signs might help mpg a bit (not endorsing this)
  • Like
Reactions: 1
You’re right. It just seems like inconsistent behaviors, that I guess could both be classified as “conservative”.
Took this today while the car wasn't moving just to make @DAC17 happy.

Got very good mileage on a country/highway trip.
See less See more
  • Like
Reactions: 2
Got very good mileage on a country/highway trip.
Pretty good but only 14 miles. :)
  • Like
  • Helpful
Reactions: 2
Wow; never seen numbers like that before!
41 - 44 of 44 Posts