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I've been meaning to do some analysis of the Ascent's acceleration vs throttle input for a long time. I think many people get worse gas mileage than they need to because of the very sensitive throttle pedal of the Ascent. After driving a couple of rental SUVs and seeing how much I had to press the throttle to even make it go, it made sense that people used to driving those cars would be doing the same in the Ascent.

I wanted to make videos will full data feeds so people could visually see it, but I'm moving into our new house and busy painting and fixing before we move furniture in.

So I did capture some data to share. I have the Torque App on my phone and have the gas pedal rating (0-50) showing on my screen along with the 1/4 mile times.

For reference, a 2019 Toyota Yaris does the 1/4 mile in 17.4 seconds at full throttle.
a 2019 Toyota Corolla CVT does the 1/4 mile in 16.5 secs at full throttle

So if I barely press the throttle and hold it (reading between 10-12 on my gauge) the Ascent will do the 1/4 mile in 19.5 seconds. That's only 2 seconds slower than the Yaris at full throttle. This same throttle input on the Ford Expedition I drove barely got it rolling.

If I press the throttle about 1/3 down and hold it at (reading 19-21 on my gauge) the Ascent will do the 1/4 mile in 16.7 seconds. That's almost as fast as the Corolla at full throttle! This is similar to the throttle input on the Ford Expedition for doing a slow acceleration while in traffic.

And full throttle (48.7 on the gauge) brought the quarter mile in 15.7.

When I drive in traffic, I barely use the accelerator. In fact when I was trying to do some of these tests, I couldn't finish the run because I was accelerating too fast and caught traffic in front of me.

Try driving around while easing into the throttle and keeping the revs down. The MPG change is huge between 10-12 on the throttle gauge and 25+. If I keep in the 10-12 range and don't exceed 75mph on the freeways I can easily get about 26mpg.

I'm guessing a lot of people are using 1/2 the throttle or more because it's so easy to do and because you HAVE TO in many other vehicles.

Some people did get decent results with the throttle remapper add-on, which made the throttle tip in less responsive. But one drawback was you couldn't get full throttle if you needed it. It's cheaper to retrain your foot, but you do have to think about it for a while. I'm betting people who came from slow throttle response cars could get back 1-3mpg by retraining their foot.

Personally, I just enjoy the turbo so much that my 22-24mpg has dropped to 19-21mpg.
 

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Good write up Kevin, I think this is helpful to get some real numbers to relate to. I agree that a little throttle input goes a long way and it’s easy to use a lot more than is required. I have the throttle percent and instant fuel consumption screens up on my MFD. I’ve always gotten the rated mileage or better this past year but notice that I can get careless sometimes and my mileage suffers.

I’ve noticed that I can easily keep up with traffic leaving a stop light using 30% or less throttle. I was fooling around yesterday on the way home and got up to 40% throttle and still didn’t feel the fake shift points, which I prefer.

It is a challenge and takes practice to be smooth with the accelerator after stopping.
 

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The turbo on the Ascent is not designed with optimal fuel mileage in mind. If owners of the Ascent want 30 mpg, they should have purchased the WRX which is 30% lighter and has a 20% smaller engine.

Who would even want to drive an Ascent this way: "So if I barely press the throttle and hold it (reading between 10-12 on my gauge) the Ascent will do the 1/4 mile in 19.5 seconds. That's only 2 seconds slower than the Yaris at full throttle. This same throttle input on the Ford Expedition I drove barely got it rolling."
 

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Discussion Starter · #6 ·
Who would even want to drive an Ascent this way: "So if I barely press the throttle and hold it (reading between 10-12 on my gauge) the Ascent will do the 1/4 mile in 19.5 seconds. That's only 2 seconds slower than the Yaris at full throttle. This same throttle input on the Ford Expedition I drove barely got it rolling."
With the number of "bad mpg" threads, apparently a lot of them. I do drive this way when just commuting and traveling around town. When I need the power or just want some fun, I mash the throttle and the Ascent jumps alive. Love having both options.

I agree, the SI drive mode like the Forester has/had would silence a lot of the complaints!

Even an "eco mode" selectable from a menu in the car's setup would help too! Just make it so that it scales up to full throttle when fully pressed down.
 
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I do drive that way and get good fuel economy.
Same way I have been driving from the start. It took me maybe 10 minutes of driving the Ascent to realize that if I press the pedal a little, and hold it, it keeps accelerating, pretty fast too.

Also, I'm curious if people have variable RPMs? With all the threads complaining about the fake shifting I was dreading it. My Ascent doesn't do that at all. It holds steady around 2100rpms until I left off and cruise.
 

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mtmra70, I have one particular place that I drive through frequently while taking my daughter to work where I have the RPM thing happen...it's an uphill section where the limit dropped to 25 mph that also includes a 15 mph school zone. It doesn't happen every time, but occasionally, some alignment of the earth, moon, the stars and gods conspire to confuse the system such that it thinks I need to accelerate when I really don't. That's the ONLY place I've experienced this thing. Otherwise, no issues and good fuel economy. I'm actually hanging just under 21 for general rural driving including a little "in town" and I can't complain about that at all.
 

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I have one of those up-slopes too. Especially when cold, Ascent will spool up to 3000rpm in a seemingly unpurposeful manner. When warmed up, it's much better, hardly elevated in rpm, and hardly complainable... but still slightly elevated.

Must be some odd case combo of torque required and torque delivering, that puts it in that revvy mode. Again, it's barely noticeable if I drive the hill with the motor warmed up.

Putting it in manual helps, but not quite all the way. When cold, manual seems to be a suggestion and not a command, and on that hill the car still wants to be in a lower gear than I'm asking with the manual shifter (I'll ask for 3 and get 2, or ask for 4 and it flips to 3, and not because I'm going too slow).

F.S.
 

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Can someone explain SI drive? Asking for a friend...
This friend had a loaner with SI drive and without reading the manual or anything couldn’t figure out what it’s supposed to do
Hi xydadx3

This is my understanding of SI-Drive. Feel free to correct me if I missed something.

SI-Drive (aka Subaru Intelligent Drive) is a throttle mapping system for the electronic throttle in Subarus. It was introduced by Subaru back in 2006(?) on the Legacies/Outbacks and has been on most Subarus built outside of the US. Around 2008 Subaru of America decided the American market would not benefit from such feature and deleted it from all Subarus built in Indiana. (Well recently Subaru of America is adding SI-Drive to some Subarus i.e. the 2020 Subaru Legacy Sport).

SI-Drive has 2 or 3 modes depending on the "status" of the car. For example the base level Impreza or Forester will only come with a 2 mode SI-Drive while the performance version (WRX or STI) will get the 3 mode system.

The modes are:
1. Intelligent (I) mode reduces the gain on the throttle. Exaggerated Example, when you step on the throttle 1/3 of the way down, the car only applies 1/4 the throttle. It dulls the response of the throttle to save gas. Ideal for highway driving.
2. Sport (S) mode can be considered the default throttle mapping. Example at 1/3 throttle , the car applies 1/3 throttle.
3. Sport Sharp (S#) mode is the opposite of Intelligent mode, Example: 1/3 throttle, the car applies 1/2 throttle. The throttle becomes really jumpy and can be fun for spirited driving.

Here is a link to Subaru Global for more information.
 

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I have one of those up-slopes too. Especially when cold, Ascent will spool up to 3000rpm in a seemingly unpurposeful manner. When warmed up, it's much better, hardly elevated in rpm, and hardly complainable... but still slightly elevated.

Must be some odd case combo of torque required and torque delivering, that puts it in that revvy mode. Again, it's barely noticeable if I drive the hill with the motor warmed up.

Putting it in manual helps, but not quite all the way. When cold, manual seems to be a suggestion and not a command, and on that hill the car still wants to be in a lower gear than I'm asking with the manual shifter (I'll ask for 3 and get 2, or ask for 4 and it flips to 3, and not because I'm going too slow).

F.S.
I believe the high spooling is related to the emissions control. The car needs to warm up meet emission regulations.
 

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MPG is a big deal to me, and I can say given the size and weight of the car and the responsiveness of the engine that I'm happy with the gas mileage. On road trips, we regularly get 28 to 29 mpg (and a few times even 30+). It does take a big hit around town, but overall we are averaging 24-25 mpg. Some years ago we had a Chrysler Town & Country van that was slightly less responsive and only averaged 20 mpg, so the Ascent is a nice improvement.
 

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One of the biggest detriments I have found around town is that the car coasts VERY well. Because of that, I notice that I used to tend to let it coast, and then press the gas, and keep repeating that. That eats gas, but is easier than steady pedal pressure at low speeds.

The gas mileage differences though, are night and day.
 

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I'm a "coaster", too, Robert...with the Ascent and with my previous vehicle, a Grand Cherokee with the Hemi. It can make a significant difference, both with fuel economy and with brake life. (108K on the original JGC brakes when I sold it and likely would have still passed PA inspection, albeit barely...disclosure, however...a LOT of highway miles)
 

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When I first started driving my 2020 Ascent, I got about 16 MPG on the first two tanks. I started watching the instant MPG meter and just adjusted my pedal pressure slightly and the next two tanks were 19 and 20 MPG. This is all city driving 100% of the time! It was definitely an adjustment from my previous car. The throttle is way more sensitive and I barely have to press it to keep it moving. Watching the instant MPG meter really gives you a full characterization of the throttle sensitivity.
 

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I agree with your assessment, Kevin, in my limited experience with the Ascent (brand new owner). I would also add that the engine response mapping for the Ascent when climbing a hill (even a small one) would result in a much higher RPM than expected. Sometimes it would rev up to 3500 RPM for really no need at all, considering how torquey the engine is. I guess Subaru wants to ensure for a smooth ride up the hill and minimize the chance of engine getting bogged down too much. I would then ease off the throttle just a bit to allow the CVT to shift up and lower the RPM.

The end goal, IMO, is to use as little engine RPM as possible while still meeting your driving needs. The lower the RPM, the less fuel you use. The engine is so torquey that I barely using any throttle at all. Although it's fun to punch it every now and then. But I still don't use that much throttle, according to the gauge.

In my short time of ownership, 1 week, I've averaged 20 MPG with all city driving. And that's with a lot of idling on the driveway, playing with all the settings. Can't wait for a longer road trip and see how the Ascent does at a consistent cruising speed.
 

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When I first got my Ascent I was around 24-25 mpg. After a few thousand miles, I started getting more aggressive with it and noticed a dip, 21-22 mpg. I'm back to driving conservatively and getting 24mpg (I blame the winter blend right now).

Never have I experienced a car in which fuel consumption is so directly related to my driving habits. Sure, I've noticed my driving habits affect fuel consumption with other vehicles, but not to this extent. Under heavy acceleration and inclines, the Ascent is very thirsty. Highway cruising and gentle acceleration, the Ascent is very forgiving.
 

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I think this is a characteristic of these small high-tech turbocharged engines from Subaru, Ford, and other manufacturers. If you're light on the throttle, they act like little efficient engines. Put your foot into it and they drink gas commensurate with their high power output. The Ascent seems particular sensitive due to it's eager throttle response. A driver needs to be particularly delicate with the pedal to get that little engine gas consumption.
 
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