Automatic braking?

Well with the adaptive cruise on it'll start braking before it's an emergency.

This is correct, it starts braking long before the emergency braking system engages. I have been driving with ACC engaged at roughly 75mph when suddenly traffic came to a quick stop. The car stopped itself gracefully while I only covered the brake pedal and never touched it. Keep in mind that Eyesight is reactive to the car directly in front and cannot predict the braking like a driver can when we see brake lights many cars ahead of us. In this situation, we would at minimum let off the gas, if not begin to brake...whereas Eyesight will not react until the vehicle in front of it does.

This is correct, it starts braking long before the emergency braking system engages. I have been driving with ACC engaged at roughly 75mph when suddenly traffic came to a quick stop. The car stopped itself gracefully while I only covered the brake pedal and never touched it. Keep in mind that Eyesight is reactive to the car directly in front and cannot predict the braking like a driver can when we see brake lights many cars ahead of us. In this situation, we would at minimum let off the gas, if not begin to brake...whereas Eyesight will not react until the vehicle in front of it does.

The caveat being you were following a car that also was initially driving 75mph and the adaptive cruise slowed down matching that cars braking...

If you are on the highway, at 75mph with adaptive cruise on but not following another car (or regular cruise, in this case, because there is no lead car to follow in this instance), and traffic in front of you is at a dead stop, the system will initiate braking and then full emergency braking, but you are still gonna smack the car in front of you.

There are several videos on youtube of people testing Eyesight. Emergency braking will completely stop the car at 35mph or less, but above 35mph you will hit whatever is in front of you, albeit the car will be slowing as much as friction allows before you hit it.

The 35mph testing was done on dry pavement, so in slippery situations you may still hit what is in front of you Eyesight or not, depending upon your speed.

Tesla has a one-up on Subaru currently, because their system not only brakes but also steers the car to avoid accidents. Maybe next gen Eyesight will start to do the same...

The caveat being you were following a car that also was initially driving 75mph and the adaptive cruise slowed down matching that cars braking...

 

If you are on the highway, at 75mph with adaptive cruise on but not following another car (or regular cruise, in this case, because there is no lead car to follow in this instance), and traffic in front of you is at a dead stop, the system will initiate braking and then full emergency braking, but you are still gonna smack the car in front of you.

 

There are several videos on youtube of people testing Eyesight. Emergency braking will completely stop the car at 35mph or less, but above 35mph you will hit whatever is in front of you, albeit the car will be slowing as much as friction allows before you hit it.

 

The 35mph testing was done on dry pavement, so in slippery situations you may still hit what is in front of you Eyesight or not, depending upon your speed.

 

Tesla has a one-up on Subaru currently, because their system not only brakes but also steers the car to avoid accidents. Maybe next gen Eyesight will start to do the same...

Well said, completely depends on if there is a lead vehicle that Eyesight has acknowledged and is following. I failed to mention that.

I have noticed though that eyesight has trouble recognizing a lead vehicle if you're approaching a non-moving vehicle - such as at a stoplight, compared to a vehicle at the same distance that is moving at a similar speed to your car. In the former case, the vehicle once locked on so late that immediately after it recognized the lead vehicle it started signaling the warning alert to brake which lead me to manually stop the car so I didn't risk an accident. I had the ACC on ~28mph and it was a straight 25mph road, so it was a situation where I could easily stop the car in time if the ACC didn't recognize the vehicle quickly enough even though it "should" have seen the cars stopped at the light on a flat, straight road sooner than it did.

This isn't a complaint or a surprise really as Subaru's ACC works really well in so many situations, but it does confirm that adaptive cruise control is definitely not near the level of Tesla's autopilot. At least Subaru is a well run car company whereas Tesla is bound to go out of business any year now since they don't actually know how to make cars yet, haha.

Adaptive cruise is good in that it automatically adjusts following distance based upon speed (given any of the four settings, eg the distance between you and the car you are following gets bigger the faster you go). I usually leave it at 3 or 4 (max) following distance on the highway, and shorten it to 1-3 in town, depending upon traffic.

If you use max distance all the time, it sometimes encourages jackalopes to either merge in your lane or enter the road in the gap between you and the car you are following. Shorter following distances discourage that, and in slower driving (sub 35mph) I am confident even the closer following distances in traffic allow the car to fully stop, even if the car in front unexpectedly slams on their brakes.

My wife's acura with Acurawatch has adaptive cruise, but that system is really only good on the highway and 40mph and over... Subaru has it beat.

The emergency braking is the same with or without ACC. Its the speed at which the car is traveling when the emergency braking kicks on that will be different.

Example: If you are driving on the interstate at what ever speed (say 60) and don't notice that traffic ahead has slowed down or come to a complete stop, the car will still be traveling at 60 when the emergency brakes kick-on at the point when the system thinks a collision is imminent. As the speeds get higher the braking distance left is not enough to bring the car to a stop before hitting the obstacle in front. However, you hit it at a lower speed than you would have without the system.

With ACC on and following a car, again say 60. If the car in front slams on the brakes, ACC will first start braking, but in a fraction of a second turn into an emergency situation and the emergency braking will kick on. At the point that the emergency brakes kick on, the car will be slower than 60 unlike in the first case. You may or may not hit the car in front depending on a gazillion other factors.

If you use max distance all the time, it sometimes encourages jackalopes to either merge in your lane or enter the road in the gap between you and the car you are following. Shorter following distances discourage that, and in slower driving (sub 35mph) I am confident even the closer following distances in traffic allow the car to fully stop, even if the car in front unexpectedly slams on their brakes.

I've found anything above 1 bar to encourage jackalopes to enter the gap between the car in front. But at that setting in rush hour driving, the emergency braking kicks on at least a few times and isn't pleasurable anymore. With 2 bars, they squeeze in but only a small portion of the car is in my lane and ES doesn't pick it up till the point that I feel unsettled and end up having to hit the brakes.

3 bars seem to keep things sane and enjoyable. They merge in front (mostly the more aggressive ones), but it has stopped bothering me as much in return for a happy commute.

At max distance I have tailgaters

3 bars is my preferred setting for the same reasons sgollapalle mentioned. Depending on the guy in front of me, I may see emergency braking come on (while using ACC) 1-2x a week in traffic on the highway. Following people that tailgate tends to cause emergency braking to come on, so I change lanes so they are not the lead car anymore.

In general the ACC has taught me to be more aware of other drivers style and avoid them. I switch lanes whenever I notice cars in front/behind me are on their phones, or when they tailgate.

With 3 bars on the ACC in rush hour traffic you would be cut off all the time here.

Yes, I noticed that when I visited NYC last year. It was terribly frustrating.. I'm very fortunate to live in an area where the morning commuters are more relaxed. Evening commuters are monsters, but in the morning everyone is still asleep!