My wife has noticed (and commented) that the ACC isn't the smoothest when in control. And I have to agree with her. I can control the speed far more smoothly than the ACC. Throttle control isn't bad, but the braking is a little abrupt and uneven.

I just had a RAV4 rental last week that had ACC, and I have to say that it was quite a bit smoother with its throttle and brake control. That said, I still prefer my Subaru Eyesight by far over the Toyota. Once I hit 30 MPH (slowing) it disengages, so no full stop ability.

 

I have a '15 Outback and a '16 Forester both with Eyesight and the Eyesight in the Outback is much smoother and quicker to respond to changes then the Forester, and the Forester will not hold a stop like the Outback will.

The latest Eyesight system with the color camera's came in the '17 Forester so I would think that model year would react like my '15 Outback but not with the stop hold.

 

Forester will not hold a stop like the Outback will.

The latest Eyesight system with the color camera's came in the '17 Forester so I would think that model year would react like my '15 Outback but not with the stop hold.

Forester isn't going to be able to hold the stop until the '19 model, when it gets the electronic parking brake. What happens when ACC slows you to a stop in the Outback is that the electronic parking brake then engages to hold you stopped. The Forester (and the current Crosstrek & Impreza models) has manual parking brakes.

So that's why the Forester does NOT hold when engaged.

 

My 2016 OB is the only car with ACC I've driven, so I can't compare, but I find the ACC to be more abrupt with throttle inputs than non-ACC cars I've owned. Particularly when a vehicle in front of me exits "radar range" the ACC pretty much mashes the throttle down. My fuel mileage also takes a small hit with ACC; actually, with any type of CC on any car -- I can always coax more MPG driving manually, not that I'm a big worrier about a few MPG. All said, I really like my OB's ACC and wouldn't trade it for any non-ACC system. I once went nearly 150 miles on a moderately-traveled interstate without touching the gas or brake pedals, and did it safely.

 

This is the 6th vehicle we've owned with some form of adaptive cruise. I find it to be quite responsive and very smooth. Typically we only use it on highways, although I have used it on a two-lane road while (intentionally) following someone for a long period of time. That was the ideal situation really...it kept a perfect distance and I didn't have to even think about follow speed.

Comparatively....the OB system is definitely smoother than some of the older models. Compared to newer models, it's still smoother than our Acura MDX. I prefer the system in my Yukon Denali though, but only because the following distance on the Yukon is tighter at highway speeds. Even set to the shortest distance, the OB leaves a gap big enough that people will try to pass on the right when you're in a line of passing traffic. I usually take over control in the OB to shorten the gap until the lane clears up, but the Denali keeps it tight. Also, I find the OB slows down long before necessary when approaching slower traffic.

 

I prefer the system in my Yukon Denali though, but only because the following distance on the Yukon is tighter at highway speeds. Even set to the shortest distance, the OB leaves a gap big enough that people will try to pass on the right when you're in a line of passing traffic. I usually take over control in the OB to shorten the gap until the lane clears up, but the Denali keeps it tight. Also, I find the OB slows down long before necessary when approaching slower traffic.

What you're saying is that the Outback reacts like a good driver, and the Delali doesn't? >

 

OK, I didn't phrase that well. The chart shows distance at a speed, but if you do the math you will see that those distances are close to the same amount of time at those speeds.

At 60 MPH you travel about 88 feet per second. So one bar is just a hair over one second following distance. A two second following distance means you are following 176 feet behind the lead car. So four bars is just over two seconds.

At 25 MPH (40% of 60 MPH) you travel 35.2 feet per second. Four bars is 95 feet following distance, while 40% of the 60 MPH following distance is 70.4 feet. This is 2.7 seconds, so they've increased spacing at slower speeds.

 

Three comments:

1. Sorry, I don't have a comparison of the 2015 Outback to other cars.
2. Almost always a driver controlling the car can be smoother and anticipate conditions better than ACC can, but it is a lot of work, which is the point. A driver may also do a worse job of controlling the car.
3. Concerning following distance, habits of drivers on crowded freeways are such that people follow at closer than safe distances and whether it is ACC or under driver control anyone keeping a reasonable distance in the passing lane will be perceived as the lane hog slow up and be passed on the right.

 

Just got my 2019 2.5L and I've been testing it the last few days. I was keen on the Subarus because they rated pretty well in many automatic braking tests published.

My opinion after a few days testing is that the braking when it approaches a slowing car is too hard. This is on full-distance setting. Acceleration is not too bad, but it's the late braking that makes me nervous with my foot hovering over the brake pedal. And that takes away some of the pleasure of the system.

It's a shame the 2019 doesn't have the Eyesight characteristics settings that the 2018 Crosstrek and 2020 Outback has. It let's you adjust how urgent the system reacts.