soopsoop Posted October 20, 2015 Share Posted October 20, 2015 (edited) i have a 2006 impreza and when i set the cruise control i works fine until i head downhill it then picks up speed about thirty miles per hour until i step on the brakes to prevent going too fast. is this normal? should i be worried? you would think there would be engine braking. it is an automatic with 170,000 on it. Edited October 20, 2015 by soopsoop Quote Link to comment Share on other sites More sharing options...
RacerX69 Posted October 20, 2015 Share Posted October 20, 2015 (edited) Cruise control on any motor vehicle is only meant to maintain the set speed, usually with an allowance of about 2 to 3 mph up or down from the set speed. The cruise control only operates the throttle. It does not provide engine braking. On vehicles with automatic transmissions there is little, if any compression braking because the torque converter does not provide a direct coupling between the engine and drivetrain. Cruise control systems are purely a convince item, never a safety device. Edited October 20, 2015 by RacerX69 Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 20, 2015 Share Posted October 20, 2015 some vehicles have adapted or regulated cruise control. That will kick down a gear or 2. But not all do.. And subarus dont Quote Link to comment Share on other sites More sharing options...
wtdash Posted October 21, 2015 Share Posted October 21, 2015 (edited) ^New Subarus DO have adaptive cruise control.>>EyeSight<<..it's becoming a standard. Your 2006 does not, and Yes it's normal for the speed to increase going downhill. Read your Owner's Manual. And please don't Double-Post....just because you didn't get an immediate answer is not a reason to repost 2+ hours later. GL, TD Edited October 21, 2015 by wtdash Quote Link to comment Share on other sites More sharing options...
Dj7291993 Posted October 21, 2015 Share Posted October 21, 2015 You can shift it out of overdrive, but a basic cruise has no way to slow the vehicle. Quote Link to comment Share on other sites More sharing options...
Wolfman01 Posted October 21, 2015 Share Posted October 21, 2015 i have a 2006 impreza and when i set the cruise control i works fine until i head downhill it then picks up speed about thirty miles per hour until i step on the brakes to prevent going too fast. is this normal? should i be worried? you would think there would be engine braking. it is an automatic with 170,000 on it. Yes this is normal. It is only recently that vehicles have begun to incorporate grade logic and have begun using engine braking to maintain set speed on the cruise. Your vehicle still requires you pay attention to your speed in hilly conditions. Quote Link to comment Share on other sites More sharing options...
Wolfman01 Posted October 21, 2015 Share Posted October 21, 2015 some vehicles have adapted or regulated cruise control. That will kick down a gear or 2. But not all do.. And subarus dont Mine is newer and does "downshift" to help maintain speed. I can watch the revs pick up when the speed increases approximately 5 mph over set speed on a downhill grade. I do not have eyesight. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted October 21, 2015 Share Posted October 21, 2015 Yeah, unlike semis which can automatically incorporate the Jake brake if it gets too fast, cars you really just need to watch it. As others pointed out, you can pull it out of OD and that'll add a minor amount of slowing. Then again, if we've become so lazy that we can't hit the brake anymore because it'd mean having to press resume, then we are doomed as a race at some point. 2 Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 21, 2015 Share Posted October 21, 2015 (edited) What?! Sloooow down (pun intended)....6 people think this is normal to gain thirty miles per hour down a hill? Am I misreading this? Sounds way off to me, none of my automatic Subarus do that and I live in the mountains. 2002 H6 automatic, it holds fine down mountains at interstate speed....is it maybe slower speeds that don't cooperate?How steep? How fast? Edited October 21, 2015 by grossgary Quote Link to comment Share on other sites More sharing options...
DaveT Posted October 21, 2015 Share Posted October 21, 2015 The hills around here, where the car will overspend the cruise setpoint, will over speed zero throttle unless you downshift. Most of these are on secondary roads, not multilane highways. This is my experience in automatics. 01 and 09 forester mostly, but any other random car I've ever driven also. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 22, 2015 Share Posted October 22, 2015 (edited) You're talking 40 or 50 mph? At interstate speeds I can set cruise control at 70mph or 80 mph and it retains that speed. Set it on the flat stretches though, setting on incline or decline is less consistent. Secondary roads here are too winding (or unmarked, or gravel, or unmaintained, or potholes....LOL) for cruise control. I might get a chance Friday to drive our automatic, I'll try to find a stretch straight enough to run cruise at a low speed. Edited October 22, 2015 by grossgary Quote Link to comment Share on other sites More sharing options...
desertsubaru Posted October 22, 2015 Share Posted October 22, 2015 My 03 Forrester auto holds a pretty close to "set" speed. As Gary said WV is very hilly yet mine wont go more then 5 mph over the set speed. There is something wrong if he hits 30 mph more then set speed down a hill. Unless the hill is a real steep grade it shouldn't do that. Quote Link to comment Share on other sites More sharing options...
DaveT Posted October 22, 2015 Share Posted October 22, 2015 My examples are 34 to maybe 50. Probably the over speed limit around 5. Some might push to around 10. I usually push the shifter to 3 at the tpp of knoqn hills, so I don't know what the ultimate would be. 1 Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 22, 2015 Share Posted October 22, 2015 My 2014 Ford Fusion will gain 10-20mph easy down hill in cruise, even when it kicks down, the 1.5l can't hold the big car back.. Mopar has had cruise that kicks down a gear since the early 00s Quote Link to comment Share on other sites More sharing options...
soopsoop Posted November 14, 2015 Author Share Posted November 14, 2015 the dealer reflashed the ecm now the cruise holds about 4 or 5 miles per hour like it is suppose to Quote Link to comment Share on other sites More sharing options...
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