When did ACC go to radar?

[skeptic]

As I understand it, the original ACC was based on a camera somewhere near the rear view mirror. According to bmwusa.com, the current ACC is based on radar. Knowing when it switched may help influence my decision of what year to buy.

 

[eNate]

Typo?

Ford insists my Flex has high beam assist. Never had it, never will.

I can't find any references to a change to radar.

 

[bornelectric2018]

My 2019 i3s, built in mid-March of this year, has camera-based ACC. Honestly, it's underwhelming, but I don't regret getting Driver Assistant Plus. ACC turns itself off regularly, whether from sun glare, oncoming headlights, or miscalculated distance. It hates vehicles parked on the side of the road, especially in turns. The most annoying part of ACC's deactivations is that sometimes it won't allow me to re-engage it immediately, requiring a preset time or distance to elapse before it is available again.

I find ACC most useful in very slow stop--and-go traffic, like freeway traffic jams, or at higher speeds on roads with fairly light traffic. It's hardest to deal with in situations where traffic speeds up and slows down between 30-60mph, as it's always a second or two behind the actual road conditions. In those cases, it's easier to just switch it to standby until traffic conditions are more favorable.

I don't have experience with radar-based systems, but I'd hope that they would be more robust.

 

[skeptic]

I can't find a direct link, it's a pop-up from within "Build your own" 2019 i3 + Rex on bmwusa.com, but the text for the Tech package is:

Technology + Driving Assistant Package
$2,350
Tap into the convenience of the latest in driver assist technology. Includes advanced features like Active Cruise Control with Stop & Go, which lets you maintain your selected speed and uses radar to bring your vehicle to a complete stop; BMW Navigation System with its split-screen display; and Advanced Real-Time Traffic Information.


If this is wrong, or even if it's just brand new, I'm not going to worry about it. I've been occasionally checking prices and trying to decide between '15/'16 or pay an extra ~30% for a '17. If they had switched to radar based ACC that just might have been enough to push me to the '17. Then again, I'm still probably 2 months from buying (need to finish remodeling my kitchen/family room first). By then the 2020s should be out and hopefully drive down the price of used.

 

[jadnashuanh]

Changing to radar could be a running change, but if it is, it's very recent. I did look at the BMWUSA website, and agree, it does say radar based. FWIW, while probably not a big range buster, the camera is much more efficient than a radar, and, at least initially with the small battery, they sweated every gram and power drain to get the car as efficient as they could at a price people would still pay. That's one reason why it doesn't have power seats or a heated steering wheel...it uses power, and in the case of the seats, adds a lot of weight for the motors.

 

[KrisM]

I had a radar based system in my F31 and I must say in the 3 years that I have had that car, that system failed less than in the 3 months that I have the i3 with the camera system. It is to sunny, it is to clouded, the much headlights from upcoming traffic, to much rain ...... there is always something that makes the camera system fail. The only failure I had with the radar system with heavy rain and at the same time driving with high speed, that is it.

 

[jadnashuanh]

Agreed, radar based systems can be more reliable under more conditions, but when every watt counts, using it in the ACC didn't meet the original design goal, and they opted for the camera which is a very minimal power draw. It also costs more as an assembly than the camera, but not a huge amount. It does offer the ability for object discrimination that radar generally doesn't, so it can detect a person or animal more reliably than a radar based system might. So, you gain some, lose some. The newer cars, with their much larger battery, don't need to be as frugal with their watts and remain functional versus the original ones.