Does cruise control limit your speed?

[FusionDiffusion]

Say you're going down a fairly steep hill with the cruise control engaged. As you pick up speed will the car do anything to limit or reduce your speed back to the set point? Some of the cars I've driven do this by downshifting the transmission (engine braking), but I'm wondering how the hybrids handle it. Does it raise the CVT gear ratio for engine braking or does the car use the regenerative brakes (or both)?

 

Also, with adaptive cruise control what happens when a slow car changes lanes in front of you and the car has to slow down faster than normal? I know the ACC can apply the hydraulic brakes to some degree on the non-hybrids, but is regenerative braking used instead on the hybrids?

 

Is there any difference in behavior with EcoCruise vs. regular cruise for any of the above? Hill descent mode?

[tombarker13ffh]

If youre rolling downhill with the cruise on and the ev is not needed to maintain speed, it will recharge the hv battery at a rate dependent on your speed, so it will limit your speed to your cruise setting, but the more the decline, the more the transmission will charge. Its the same as regen braking, its just doing it without the brakes. Eco cruise will maintain your cruise speed less aggressively than normal cruise, so it will accelerate slower when hitting an incline instead of revving the engine high immediately. ACC, i dont know anything about.

[tombarker13ffh]

Although ive never seen it, i would assume if you go downhill long enough to fill the battery, the ev mode will keep coasting and it will not use any more battery.

[acdii]

Say you're going down a fairly steep hill with the cruise control engaged. As you pick up speed will the car do anything to limit or reduce your speed back to the set point? Some of the cars I've driven do this by downshifting the transmission (engine braking), but I'm wondering how the hybrids handle it. Does it raise the CVT gear ratio for engine braking or does the car use the regenerative brakes (or both)?

 

Also, with adaptive cruise control what happens when a slow car changes lanes in front of you and the car has to slow down faster than normal? I know the ACC can apply the hydraulic brakes to some degree on the non-hybrids, but is regenerative braking used instead on the hybrids?

 

Is there any difference in behavior with EcoCruise vs. regular cruise for any of the above? Hill descent mode?

Yes. In a standard auto transmission it will downshift to maintain your speed. In the Hybrid it will apply braking. Going down the mountain (if thats what you want to call those hills between IL and FL), the car was on cruise and it would apply braking as needed.

 

As far as I know, it uses whichever braking method it needs to slow the car down when using ACC. The brake lights come on, the regen circle shows and the car slows.