[Berber]

My car is a 7 month old 1.6 diesel. Today I noticed that when travelling to work at 70mph with the cruise control on it surges. This isnt a big issue and it is only because the roads are quiet that I notice it. The surge is gentle (if that is the best descriptiion) and pulses every 1.5 seconds. I suspect it is how the constant speed is managed but am sure it never used to do this.

Am I being paraniod? Do other Hyundais do this?

I have 8.5K miles on the car.

[h20melon]

My cruise control does that occasionally, mainly when there is a gentle downhill slope on the freeway at 100km/h

I believe it will use up more fuel as basically it is accelerating then decelerating etc...  Even on the flat i see the CC uses more fuel than using your foot.

[Berber]

Thanks Melon. I have the same issues when going uphill or downhill. This, though, is when it is on the flat.

[Shambles]

Mine is slightly younger and does occasionally 'hunt' to keep the speed right. It's barely noticeable but it is indeed there...

[eye30]

Mine does it if say i'm doing 60 mph in 6th so by increasing speed slightly it goes.

If i drop down to 5th it goes as well at 60 mph.

As revs increase when i drop to 5th so must be connected etc

[Phil №❶]

Doesn't happen in the auto 

[Berber]

Thanks Shambles. It is nice to know it isnt a potential problem. 

[FatBoy]

Mine does the same at 100 km/h. If I set it at 99 or 101 km/h it doesn't surge.

[Mike SX]

I'm glad to report that mine is every bit as good as the Bosch Jetronic fitted to the Mercedes.
Does not waver at all 

[Dazzler]

I'm glad to report that mine is every bit as good as the Bosch Jetronic fitted to the Mercedes.
Does not waver at all 

Jeepers! A friday arvo car with Wednesday Cruise control 

[Mike SX]

Jeepers! A friday arvo car with Wednesday Cruise control 

Yep, but it took 4 years of hell to get the dealer to fix all the problems 
The car has performed perfectly (for the last 6 months)   
Love it, as much as the day I purchased it 

[Dazzler]

Jeepers! A friday arvo car with Wednesday Cruise control 

Yep, but it took 4 years of hell to get the dealer to fix all the problems 
The car has performed perfectly (for the last 6 months)   
Love it, as much as the day I purchased it 

 

[Surferdude]

Mine's not diesel of course but I have never experienced a surging problem, nor a gentle "creep up" in speed as I used to get with my 2 Subarus.
However, I agree with comments above, that using CC is heavier on fuel useage than if you use your foot (carefully).

[Phil №❶]

CC does not preempt inclines so it will always use more fuel. It is cheaper to accelerate on the flat to climb a hill, than to feed more fuel to the engine once a hill is encountered.

[Surferdude]

CC does not preempt inclines so it will always use more fuel. It is cheaper to accelerate on the flat to climb a hill, than to feed more fuel to the engine once a hill is encountered.

Absolutely.

[Berber]

I thought the CC would allow better fuel consumption. It just goes to show........

[Surferdude]

I thought the CC would allow better fuel consumption. It just goes to show........

TBH Berber, It probably does in a majority of cases. My observation is that the average driver doesn't pay anywhere near enough attention to maintaining their speed on the open road, often speeding up or slowing down as their concentration wanes. So CC would help them.

[Phil №❶]

Yes, SOME drivers are a bit heavy handed when changing speeds, but in very hilly country, it is better to drive without CC. Remember the CC is a 1 speed setting, unless you're constantly changing it, so it works best on freeways & country roads. Luckily, I have these conditions, so I use it quite often.

[eye30]

When i use cc i have toggled between on and off depending on the traffic conditions.

[Berber]

I think I know what is causing the gentle surging. I think it is the tuning chip as it didn't happen before it was fitted. This would make sense.