Cruise control won't hold speed

[Gimli]

From a horsepower to weight ratio perspective, even the V6 Genesis ranks higher than the majority of cars.

Going down a hill has nothing to do with horsepower. Gravity does.

It's no heavier than any other luxury car and they don't have this problem.

What other specific luxury cars have you driven that didn't have this "problem"?

 

[Mark_888]

Going down a hill has nothing to do with horsepower. Gravity does.

I thought the complaints were about an incline, not decline.

 

[Gold Z]

"What other specific luxury cars have you driven that didn't have this "problem"?

Gimli, you obviously have no idea how a cruise control works. Weight is not the problem. Cruise controls work off sensors to either open or close the throttle to maintain a constant speed. There is usually an means of adjustment somewhere in the system. My old 99 Chrysler Concorde weighs as much as my Genesis and had a much smaller engine and it could hold a speed. Here in north Texas we only have gently rolling small hills. Stand in one spot and unless something blocks your view you can see all the way to the horizen. There isn't a mountain to be seen. As to what luxury cars I've driven, several different Mercedes and BMWs with a couple of Lexus thrown in. All could hold a speed in cruise mode.

 

[Mark_888]

I wonder if part of the problem may be related to the transmission and/or throttle. Even with the 3.8 V6 I notice that it is not always easy to slowly increase speed. That makes the car more responsive, but it may make tuning the cruise control a little more difficult.

 

[CanukV6]

"One thing I would ask is: how heavy were those other cars you're comparing against? The Genesis is fairly heavy at 4k lbs and that will have a effect on just how well the cruise control can hold speed on inclined roads."

I have a 1987 Mercedes-Benz S-Class that weighs in at close to 5000 lbs and it holds speed uphill, downhill and on the level much better than my Genesis and it has only 148 HP & 201 lb-ft of torque (its a Diesel). But as 'Gold Z' said, weight is not the issue, it is the ability of the Cruise Control system to respond to changes in speed and load. Obviously the system used in the Genesis isn't as accurate or responsive as most others that I (and it seems many other owners) have experienced. The Genesis (V6 or V8) has plenty of power and a 6-speed transmission, so the problem is in the Cruise Control electronics not the ability of the car to maintain speed up hills.

 

[Gimli]

Gimli, you obviously have no idea how a cruise control works. Weight is not the problem.

Why so much hostility? What do you know of my background? You should be more careful with your eThug attitude, I'm quite certain you're missing out on a lot of good information because of it. I'm trying to find out more specific information to see if that is indeed a real problem or a perceived one and, instead of actually answering the question, you choose to attack the person who asked it?

Generalizations such as the one you stated in the post I responded to are absolutely useless in trying to troubleshoot what may be perceived as a problem. Specific information about exactly what models you're comparing against are useful. I asked you a question whose point was to get useful information instead of conjecture and generalization.

It's ok though, I guess you don't really want a solution or explanation, you just want to vent and bite the head off of the people trying to help. That'll teach me I'm sure your service advisor will be just as receptive to it...

 

[CanukV6]

I agree there is no need for hostility and I'm not sure if GoldZ meant it that way or not.
Rule #1 when solving a problem is that 'There are no dumb questions'. Any input is valued and nobody should refrain from participating for fear of being ridiculed. The whole reason we join these forums is to share information and ideas.

 

[Gimli]

I have a 1987 Mercedes-Benz S-Class that weighs in at close to 5000 lbs and it holds speed uphill, downhill and on the level much better than my Genesis and it has only 148 HP & 201 lb-ft of torque (its a Diesel).

There's three things here that work in your Mercedes's favour: one is the turbo-diesel engine. The compression in turbo-diesel engines is usually much higher than in gasoline engines, which means they can more easily use the engine to brake.

Another is the 4-speed transmission. Contrary to popular belief, more speeds in an automatic transmission actually works against the cruise controls ability to adjust speed as there is less torque available in overdrive speeds. The cruise will not usually force the transmission to downshift to recover lost speed unless there is a significant (i.e. 5-10+ km/h) reduction in cruising speed caused by an incline.

The last thing, looking at specs of the W126 S-class available online, is that it looks like it's curb weight is only about 3,600 lbs.
http://en.wikipedia.org/wiki/Mercedes-Benz_W126

 

[CanukV6]

I agree that the diesel compression will help hold speed on a downhill road, but the point is that the system in my M-B will hold speed much better than the Genesis uphill (including shifting gears), on the level and downhill. I have also owned BMW's Lexus and even a Ford 500 that had far better speed regulation when in cruise control than my Genesis. BTW Long Wheelbase Diesel S-Class weighs much more than 3600 lbs

 

[Gold Z]

Why so much hostility? What do you know of my background? You should be more careful with your eThug attitude, I'm quite certain you're missing out on a lot of good information because of it. I'm trying to find out more specific information to see if that is indeed a real problem or a perceived one and, instead of actually answering the question, you choose to attack the person who asked it?

Generalizations such as the one you stated in the post I responded to are absolutely useless in trying to troubleshoot what may be perceived as a problem. Specific information about exactly what models you're comparing against are useful. I asked you a question whose point was to get useful information instead of conjecture and generalization.

It's ok though, I guess you don't really want a solution or explanation, you just want to vent and bite the head off of the people trying to help. That'll teach me I'm sure your service advisor will be just as receptive to it...

"What other specific luxury cars have you driven that didn't have this "problem"?

Be careful not to use quotation marks in an attempt to emphasize a word (the kind of thing you see in grocery store windows—Big "Sale" Today!). Underline or italicize that word instead. (The quotation marks will suggest to some people that you are using that word in a special or peculiar way and that you really mean something else—or that your sale is entirely bogus.)

When you used quotation marks around the word problem it indicated to me that you did not believe I had a problem. That made me mad and I responded. If it upset you so be it. You seem to be the know-it-all of the forum so you had better grow a thick hide as I am sure you will also upset other members from time to time. I know nothing of your background, I only know you don't know much about how cruise controls function or you wouldn't be asking questions about vehicle weights and what other luxury cars I have driven. Neither has anything to do with my "problem".

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[tombea]

Resurrecting this old thread, I have had my cruise control checked by the dealer. I was told that 3MPH+/- was acceptable for the 3.8 Genesis. This is unacceptable and if I was on the road a lot I would trade this car. I had a 1996 Maxima that held the cruise dead-on, especially going uphill. My 2002 Infinity does the same, so perhaps Nissan took care of this problem years ago. My 2002 Boxster won't lose more than 1MPH uphill in 6th gear. So I have a real problem sympathizing with Hyundai engineering.

Possibly on a related problem,I have had the car in twice for transmission problems. Again, Hyundai says it is 'within' specs. This week I was in Roanoke VA and the transmission made a horrible grinding noise, the car hesitated a few times before it ran normally. The only thing I know to do with this outstanding transmission is to use my Infinity for my road car and drive the Genesis until it is towed to the dealer.

 

[NOLa]

All this much drama over 3+/- mph?

Really?

 

[Gold Z]

All this much drama over 3+/- mph?

Really?

Absolutely. I had a friend get a speeding ticket for 3 mph over the limit on I44 near Oklahoma City. Granted that is very unusual it still happens and I don't want any speeding tickets. I spend a lot of time on the highways so it is important to me.

 

[tombea]

All this much drama over 3+/- mph?

Really?

Most definitely. I see that you don't drive a lot on the Interstates using a cruise control.

 

[NOLa]

I have had a 2009 V-6 Genesis and a 2011 V-8 Genesis and now an Equus.

I have an ill parent 400 miles away and drive to see her on a regular basis, about every 3 months. Past two years it was another parent who was chronically ill and has since passed. Since 2008 I've owned these Hyundais, I have been making these frequent trips, and never once have I been left standed. The driving on these trips is almost exclusively interstate.

I use(d) the cruise all the time on these trips and get great gas mileage doing so. I love the smart cruise control, by the way. It has an indicator that shows the MPH picked. The smart cruise will brake to slow the car down.

On all those 8 hour (16 hour round) trips, in all of those Hyundais, I never once noticed that the cruise was not holding to exactly the mph set. If it has a variable of 3 miles per hour, it's not a code to me.

I guess it's all in a personal perspective. This is not something I can get worked up over. I hope in one way or the other, you get resolution with it.

NOLa

 

[scottdk]

All this much drama over 3+/- mph?

Really?

+1

 

[waveman]

My cruise control seems to hold the set speed quite well, though I've only verified that with the speedometer, which is itself likely subject to error. However, there are probably conditions where inputs to the system (e.g., a car that was in front of you gets out of the way AND you are on a downgrade) where it may go a bit over the set speed before it reacts by backing off the throttle.