tejanp

I got a ticket last weekend and was perplexed because I normally set my cruise at 9 above but the trooper clocked me at 13 above. I observed my car on the rest of the drive and it appears that on downhills and uphills, it does a very poor job maintaining the set speed. Very annoying. The trooper caught me going downhill but very disappointing on the manufacturer. My BMW did a great job at keeping the set speed. Just wondering if anybody else has noticed the same or is it just my car?

er34

Cruise control doesn't utilise brakes to slow the vehicle, it typically just downshift a gear and use engine braking. On steeper downhills, it's difficult to maintain speed just by using engine braking alone. If it were to downshift more than 1 gear for added engine braking, people would also start complaining that the engine is "loud" for no reason.

Actually, I think the reason your BMW didn't have this "problem" was because it has more rolling resistance(either due to friction or aerodynamics). I find the GS is particularly good at cruising at higher speeds - I accelerate up to a certain speed, and let off the throttle and it can take me a pretty long way compared to other cars.

jordanhigg

Great write up!
I have also noticed the rolling resistance in many cars and it varies a lot. All my cars have gone up 2-3mph on a downhill, this is why I set the cruise at 7 mph above.
also if the car down shifter more to slow you down, it would lose some mpg.

signdetres

Are we talking about standard cruise control or DRCC? I've driven downhill on a stretch of road with a speed limit of 45 (could be 50) a few times now and have noticed the same behavior each time. My GS downshifts 4 gears (I've counted) to maintain speed but as a result was able to fairly easily maintain the set speed without going over it more than 3-4 mph. Over on the RX side of the forum, they too notice ~4 downshifts or so when using DRCC.

MustangSal

Why 9 over? Some places cops will pull you at 5 over. Just wondering if there is an acceptable speeding barrier between 9 and 10 mph over the posted speed limit. Besides the point...

As far as the car holding CC speeds up and downhill, I hadn't really taken notice what the car was doing in either respect.

jordanhigg

Ive asked multiple highway oratory and they say the threshold is above 7

thays just highway. No clue city streets

twylie

iTrader: (3)

At least in my state (GA), speed detection devices (radar, laser) are generally not admissible as evidence of speeding <10mph over the limit, except when used by Georgia State Patrol. Local police can still use pacing or timing over a known fixed distance to determine a speed between 1 and 9mph over the limit and issue a ticket on that basis.

Bottom line, it's unlikely that a local will ticket you for <10 over due to the extra effort. As far as GSP, they can ticket you for anything, but 9 over seems to be a reasonably safe cutoff given how fast traffic flows. Plenty of targets going 15+ over to draw fire away from us that go 9 over. :-)

MustangSal

That is very interesting. I'm in VA and now must check into that myself.

I think the natural flow of traffic here on the South Side (Va Beach) is about 10-12 over posted. We have a couple saturated kill zones where there are more detecting going on but generally they just have rolling hot zones and pull indiscriminately ... by that I mean the fastest person over the average flow who doesn't see the bear in the woods.

shrinkwrap

Of the many cars I've had with CC, the 350 is the worst at maintaining a set speed. Unless the road is perfectly flat, it is herky-jerky, hunting for the right speed/gear to maintain. As a result, I don't use it much. Annoying in a high-end car, but I can live with it...

bclexus

I could care less if any of my vehicles have cruise control. I've never liked it...and therefore I never use it. I feel less 'in control' when using cruise control. I have the need to feel in full control and not having control of the accelerator just doesn't agree with my driving style. The same would apply if a 'system' took over the steering of the vehicle.

Htony

I guess you'll never drive self driving car......

bclexus

If it is self-driving I will not be driving it...

twylie

iTrader: (3)

I have family in VA and am back up there multiple times each year. My attorney friend in VA warned of tickets of 80 or greater. In VA, 80+ or 20 over posted is reckless and actually a misdemeanor, not just a moving violation. He said he gets at lest a couple calls a month from people living out of state that got ticketed for 80+ that didn't realize it was a criminal offense and their $200 speeding ticket is now $1,000+ to have an attorney deal with it if they can't travel back for the court date. I drive 7-8 over at most in VA now. :-)

drgrant

Depends on the state and the town. In MA the general unwritten rule is MSP is 10 over is completely safe, (eg, on the highway) for cattle/lazebag traps or casual patrols, and off highway you're looking at 5 -10 mph depending on the town and the situation. In "revenue collection rhetoric towns" (basically figure any small town with less than 10 units active at once with little to no crime, so all they do is collect tickets) it's probably typically always set to 5 over or at the absolute most.

-Mike

drgrant

I've used mine quite a bit and I find absolutely nothing wrong with it- then again, IMHO the control is no different from Toyota's other CC implementations, so the car more or less acts just like my 09 and 10 Camry LE's did. If you hit a big hill, yeah, it's not going to brake, and its not going to downshift aggressively either, but if you know how to run it, the whole thing is a non issue.

-Mike