I recently replaced (well am in the process of replacing) my 2003 Mitsubishi Montero with a 2011 Mercedes E-350 Bluetec. I spend a lot of time in San Diego on the freeway with various amounts of stop and go and intermittent traffic. The adaptive cruise control has quickly become one of my favorite features of the car. But here is the kicker:
It is a tool, just like normal cruise, it is not a substitute for paying attention or driving the vehicle. In fact just like your normal cruise and using coast/accel/resume to try and maintain your speed best results come from "gaming" the system. I would say that it does not feel to me like it reduces my need to pay attention.
Let me give you a couple examples where its amazing and really reduces the stress level of driving. You are driving along like I did from Arkansas (where I bought the car) back to San Diego. The interstate is 2 lanes and you are doing a good clip of 75mph, semi truck in the right lane decides to pass another truck. Cruise sees the truck pull out shows you the speed differential between the two of you and lets off the gas usually slowing to match the trucks speed without even needing to use the brakes. You follow the truck at a safe distance and as soon as the truck gets out of your lane the car speeds back up to your intended speed.
Your typical highway commute at least around here has people doing a lot of very intermittent speeds. Guy does 72, not 70 or 75. Guy messes with phone or hits a hill and slows down then speeds up etc. This is another place where the car maintaining as close to your desired speed as it can is really nice. You don't have to worry about mister 71-74 mph guys constantly changing velocity.
Traffic is at a complete stop, then moves a little bit, then stops etc. The distronic in my car can brake to a complete stop, it can also resume driving if you are stopped for less than 3 seconds. After 3 seconds you need to hit the resume on the cruise or press the gas (the gas pedal causes a much less smooth disengagement of the brakes etc however). Whats nice is the minimum speed for its desired speed is 20mph and can be enabled once you are already stopped in traffic. This greatly aids in the annoyance of creep, stop, creep ,stop, creep creep, stop
Places the cruise control is DOESNT WORK.
When traffic just suddenly comes to a stop, I would not trust the cruise to bring everything to a halt.
Erratic acceleration and deceleration behavior of the moderate to severe degree. If people are going from standstill to 50 to standstill it's not the time or place to use it even if it might deal with it.
All in all I love the system but its at its best when dealing with minor to moderate fluctuations in speed. I find it works best to have your desired speed within 20mph of your current speed IE in stop and go I keep it at 20, when we hit 20 I set it at 40 desired for smoothest engagement. If I set it to 80 then the car over accelerates during openings and has to brake more etc.
That being said I will still keep my NA miata for when I want an engaging driving experience. But for commuting and family trips the car and this feature of the car really help make it easy to drive for extended periods.
