Do any of you get better mileage using radar cruise control or by driving manually? I have been using and setting it at 65mph using the full 10 car length sensor. Thanks.
Intuitively, I would say less. Reason being the majority of drivers are on the roads are idiots and speed up just to slam on the brakes and/or stop. You shouldn't want your car to follow that poor driving.
The reason I ask this is because I notice the adaptive cruise control is sensitive and slows down whenever someone cuts into my lane (since I am giving 10 car lengths in Los Angeles!...how nice of me.) and triggers my radar to slow down the vehicle until the car veers off into another lane. Once the car is gone and the lane opens up, the car speeds up faster than I would if I were driving it manually.
The best mpg is had when you drive as if you have no brakes. You are not doing this, so you are not getting the "best" mpg. However sometimes it is impractical and the difference between 50mpg and 45mpg is not worth endangering yourself on the road. But since you are already leaving 10 lengths in LA traffic, I would say you are either not worried about road rage or are used to being cut off and it doesn't bug you. In either case I would drive with the DRCC off. Pick a distance and maintain manually. When someone cuts you off don't slam on the brakes just get right up on their bumper as if they don't exist. Generally by that point or right after they will speed up enough and you will have slowed down enough from drag to have a safe distance again or they would have cut out into another lane.
That is what I was thinking too. BTW...I will be the one that looks like I have road rage when I start to creep up behind everyone that starts cutting into my lane.
I really like the DRCC and use it every day. I keep it on the short range and seldom notice it adjusting the cars speed while on the highway portion of my daily commute. I've always liked cruise control for highway driving. DRCC is great safety feature.
I have a feeling someone could get really great gas mileage with it if they set it on the shortest following distance and followed a semi truck with a heavy load. You obviously can get their draft but a heavy loaded semi slows down going up hills and speeds up going down them. This is best for MPG. Disclaimer, it is not safe to draft.
I find that using CC when roadway is relatively flat and traffic light then the computer can adjust faster than I can and will make excellent choices. If hills, up or down, then turn it off. Heavy traffic, off. Cut off and then accelerate too fast, turn it off. It's real easy to resume. I would add that since I travel some of the most heavily patrolled roads in North America and there is lots of construction I am willing to sacrifice MPG for no tickets and the waste of time that getting one entails so cruise works quite well in those circumstances. There is no single way to drive, use the techniques that achieve your objectives whether it's most MPG, fastest trip, least stress …
I would say "without" with net you better mpg but it depends on the terrain. In LA traffic, DRCC is definitely convenient. To achieve better mpg, you want the throttle position to hold and the speed to vary and you 'll want to minimise hard braking and acceleration which the DRCC tends to do (well, harder than you normally would do anyway).
Ya, I can imagine DRCC in CA is convenient but not near as efficient with cars constantly cutting into and out of your lane in front of you. Like I said earlier. I think it would really shine on the open interstate following a truck. (again, not the safest thing in the world, although with DRCC it becomes a bit safer)
