# Cruise control - maintains speed except any down hill!



## minsik (Oct 24, 2013)

Hi,

After a bit of driving in the Sri-V cruze, 6111km, we find that the cruise control is not appearing to slow the car down at all when any sort of downhill gradient. It this normal? Tried setting the speed of the cruise control down and down while travelling down hills but doesnt seem to have any slowing effect at all. 

Travelling on most level or very slight or uphill gradients the cruise will maintain speed quite well. Is this a feature or design limitation?

Travelling from Gosford back to Sydney there are quite a few steep hills where driving with cruise control is nearly useless as with the cruise set on and speed of 100km/hr the first downhill gradient the car goes faster and faster and then to keep even close to the speed limit have to apply the brakes which turns off the cruise control. 

Other vehicles I drive like Ford Territory, Iload i30 van - aftermarket and a Ford Ranger 4*4 appear to attempt to maintain speed downhill. 

any comments appreciated. 

Minsik


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## Aussie (Sep 16, 2012)

With a really tall 6th gear and a relatively small engine that has a lower compression to allow for the turbo that is what I would expect. Auto doesn't help either. If we get to go on that trip I will let you drive my diesel for a bit and you will see what 16.5:1 compression does for engine braking. Aussie.


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## obermd (Mar 3, 2012)

Aussie hit it on the nose. Between the small displacement engine and the efforts GM put into reducing rolling and aerodynamic drag there really isn't anything to slow the car down.


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## grs1961 (Oct 23, 2012)

Even my thoroughly-run-in manual diesel (75000km) will cheerfully roll down enough of a gradient gathering speed.

Going into the tunnels under the Yarra, or the ones under Ringwood I have to tap the brake every now-and-then until it flattens out.

If there is enough of a slope to defeat engine-braking and aero-braking, you will speed up, and the Cruze _is_ designed to be as efficient as possible.


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## minsik (Oct 24, 2013)

Thanks all. I suppose the strange thing is the expectation that cruise will maintain a speed (within limits but doesn't apply to brakes!) and that's explained well with the smaller engine. Seems a bit clearer now. 

strange how one discovers things as time goes on.


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