Last post on Apr 07, 2011 at 10:11 PM
You are in the Volvo XC60
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Volvo XC60, Volvo S60, Safe Driving, Safety Technology
#1 of 10 Volvo XC60 (MY 2011.5) Adaptive Cruise Control experience
Mar 01, 2011 (11:35 pm)
The adaptive cruise control (ACC) now includes the queue assist feature which can take the car to a complete stop and resume automatically. Today during rush-hour, on a 6-lane highway with signaled intersections, I went 5 miles in stop-and-go traffic without pressing the brakes once. A fairly awesome feat.
The ACC went as fast as 60 mph between stop lights going along with the flow of traffic. I had the ACC set to 75 mph but the car in front of me regulated the speed for the entire 5 miles. I didn't change lanes and I stayed in the left lane the entire time.
The only thing required after a prolonged stop was to press the accelerator to get the car moving a little and then the ACC took over accelerating with the car in front of me.
Even though I didn't have to press the brakes, I covered the brakes the whole time of course. It was a bit unnerving to trust the ACC to stop but it did so without being too jerky. It looks like Volvo will continue to build on this technology because there is a lot of room for improvement.
The upside - Look Ma, no feet! It's pretty cool. No one around me would even guess a computer chip was doing the accelerating and braking. The ACC did a decent job of keeping up with traffic. No one cut into my lane in front of me, so the ACC kept a reasonable distance to the car in front when braking and accelerating. Though I did adjust the following-distance setting as needed.
The downside (a few things)-
1) It will not automatically resume after a prolonged stop. It would better if after a prolonged stop the ACC automatically accelerated with the car in front and gave a short warning beep. This would save me from pressing the accelerator.
2) When making a right-turn at an intersection, the ACC loses the car in front and gives a small beep as it is disengaged. Also, when on a straight stretch of road, if a car moves into the lane within 1-2 car lengths, the ACC doesn't recognize the car until it is 2/3 of the way in the lane. The ACC should scan and track a wider area in front of the car. It should track the leading car when it turns. It should also see cars coming into the lane, especially ones that are within a few car lengths (it instead accelerates or continues as if nothing will be there).
3) The first time I had to hit the brakes after my 5 mile journey was making a left-turn from the highway. The car in front of me continued straight, so as soon as I got in the left-turn lane the ACC started accelerating. It was blind to the line of stopped cars 200 feet ahead (approx. 10+ car lengths) and there was no way I wanted to see if City Safety would kick in to stop me. It would be better if it did track 300+ feet ahead (the 2012 Audi A8 can) and brake accordingly.
I know with City Safety the goal was not to have the driver rely on technology, so the braking is last second and abrupt. But why? If anything City Safety should give early warnings that it will engage and gradually slow down as soon as a collision with an obstacle is predicted. The braking force in the manual is listed as 'full' so it doesn't make much sense for it to go around slamming on the brakes when it could come to gentler stops instead. So there is a gap where ACC doesn't want to slow down and City Safety doesn't want to kick in.
Honestly because this is a Volvo, the technology package should become standard (ACC, lane departure warning, distance alert, and collision warning / pedestrian detection with full auto-brake). Then maybe the ACC would work better with City Safety.
Wish list - The ACC doesn't detect stop signs and traffic lights of course. Granted that's a few years from now, but combined with GPS, the ACC could know when a stop at an intersection may be needed.
So far the ACC is an interesting experience and a bit surreal. Go Volvo!
#2 of 10 adaptive cruise value
Mar 02, 2011 (5:54 am)
Thanks for this post. I've test driven the ACC on s60 and found it interesting. I like the safety aspects -- but wonder if I would commonly use the ACC around town or on short 10 mile trips. Do you think it's worth the extra $2100? I think city safety (which is standard) is only good under 18mph -- so won't help you if you are traveling faster and about to rear-end car in front.
#3 of 10 Re: adaptive cruise value [georgec1]
Mar 02, 2011 (6:27 pm)
Quick answer: no, probably not worth it alone. But the companion Collision Warning & Pedestrian Detection with Full Auto Brake is probably worth it as an insurance policy (even though it's unproven and gives no indication that it would / is working).
The ACC is more a novelty with a wow factor than a true convenience. To me it's worth the price because I really wanted the Pedestrian detection and collision warning. The ACC is just an added bonus.
The ACC is probably fine-tuned for long highway trips so it really needs a "city mode" or some fine tuning for stop-and-go traffic to be worth the cost alone for most folks. When the car in front of me drives poorly with quick braking and little anticipation, the ACC does the same.
I try my best to smooth the braking and lessen the acceleration lag by continually adjusting the speed and following distance on the ACC controls which shows it really needs some fine tuning. Though, note that I'm basically accelerating and braking around town using ACC instead of my feet, except for that initial acceleration after a 3+ second stop and when I come to a stop sign or red light with no car in front of me.
I don't plan on using the ACC when I have passengers because it's a bit jerky. I also won't use it when I'm in a hurry because it reacts slower than I would in accelerating and braking. If you want the ACC to work well when driving around the city, maybe wait a few years because I feel like a beta tester discovering all it's flaws. But I can't wait to give feedback to Volvo and maybe get a software update one day.
IMHO, if the ACC can work up to 125 mph, then City Safety should work at these speeds as well to detect and avoid obstacles as much as possible. I think Volvo is just being slow and cautious with the roll-out (and usefulness) of these features.
#4 of 10 anyone else?
by steve_ HOST
Mar 15, 2011 (8:05 pm)
Anyone else using adaptive cruise control?
A reporter is interested in speaking with anyone who is willing to share their recent (last 6-9 months) experience with ANY of the following systems: adaptive cruise control, collision warning/crash avoidance, blind-spot warning, pedestrian detection, self-parking, Ford MyKey or MyTouch, Ford Sync's cloud-based voice-activated features (directions, weather, sports, stock quotes, movies, restaurant/hotel info, etc), in-car on-demand ipod downloads.
If you are interested in commenting on your experience, please reply to predmunds.com no later than 5pm EST on March 16, 2011 and include your name, state of residence, the model year of your vehicle and your phone number.
#5 of 10 adaptive cruise control on city streets
Mar 15, 2011 (11:56 pm)
I just uploaded a YouTube vid that shows how the ACC performs off the highway.
The ACC needs tweaking for city traffic. It should have smoother acceleration and braking for prolonged low-speed, stop-and-go traffic.
#6 of 10 Re: adaptive cruise control on city streets [juxta]
by steve_ HOST
Mar 16, 2011 (7:08 am)
Interesting. I think most owner manuals recommend that you not use regular cruise control in traffic.
Ford says that their adaptive cruise control is effective in normal commuting down to ~20 mph. Looked like you were below that speed at times.
Kind of spooky seeing you drive in traffic with both feet flat on the floor.
#7 of 10 Re: adaptive cruise control on city streets [steve_]
Mar 16, 2011 (11:59 am)
"Do not use Adaptive Cruise Control in demanding driving conditions such as city driving or other heavy traffic situations..." They have a ton of disclaimers on every page of the ACC section of the manual.
In the vid I only moved my foot away from the brake for a few moments for emphasis. I always keep my foot just above the brakes in case something goes awry. I don't trust the car at all.
Volvo has a goal to make "completely safe" cars by 2020. I guess that means a car that drives itself so I'm helping them get there as a beta-tester, I suppose. I have no desire to be a crash dummy though, especially with a two-week old car, so I'm just testing these safety systems occasionally to see their limits.
One benefit I've discovered already is that ACC removes some of the emotion from driving. With my foot not on the gas and brake, I don't feel as controlling and judgmental of the cars around me. I don't care if someone is a slow poke, or if someone cuts in front of me, because I'm not "driving". I feel as though I'm just along for the ride.
#8 of 10 gas, regular or premium? performance and mileage
Mar 16, 2011 (12:23 pm)
I just finished the first tank of gas (the tank was full when I picked up the car from dealer and I assumed it was regular) and the mileage is 324 miles ( can't see the gas indicator bar at all, although I really want to keep driving for another 10 extra miles but I did not want to take the chance) It was 30% city and 70% freeway driving.
I filled up the tank with premium ($4.20/gallon in California, 16.87 gallons then the pump stopped) and want to see any mileage difference this time. Does this mean there is still 1.63 gallons of gas left in the tank before I refueled? Is it really necessary to use premium for this car in term of performance and mileage? I had a Lexus and I did not see any difference at all.
#9 of 10 Re: gas, regular or premium? performance and mileage [sjsm]
Mar 17, 2011 (10:59 am)
I've seen very little if any change in MPG when using either regular or premium on our XC60
#10 of 10 Re: gas, regular or premium? performance and mileage [mikey38]
Apr 07, 2011 (10:11 pm)
Thanks for your reply. ( I just read your post.)