Cruse control with grade descent

[Kaleido]

I don't hit the highway too often, but today I noticed while I was in cruse control at 70 mph I was going down a long hill about a mile long and my HVB was at about half, so I hit the grade descent button and my speed stayed at 70 mph and my HVB climbed to full. Pretty cool!

[neod192]

What does that do to your MPG?

[Kaleido]

What does that do to your MPG?

Right now my mpg is 37.8, the highest I've seen in 4 months! It usually hangs around 36/37 mpg, but now it's warmer here in north Jersey.

[hybridbear]

I don't hit the highway too often, but today I noticed while I was in cruse control at 70 mph I was going down a long hill about a mile long and my HVB was at about half, so I hit the grade descent button and my speed stayed at 70 mph and my HVB climbed to full. Pretty cool!

 

Grade Assist is really nice for driving in the mountains. We used it when we drove to Cali in January. It will maintain your speed whether using CC or not. On CC without Grade Assist turned on your speed will climb when descending a long hill. Since this recharges the battery very quickly it's good to try to get the battery SOC as low as possible before hitting the long downhill if you know it's coming.

 

I also even use it around our rolling hills in Mpls to make sure my speed doesn't climb too much when driving in the city. There are a few hills where it's easy to go from 30-40 MPH and then the cops will sit at the bottom watching for speeders. Grade Assist is awesome in those situations because you can leave it on all the time and it won't regen and slow you down any faster than normal, it will only regen aggressively to keep your speed from increasing. I think this is a far superior design to the "B" mode in the Toyota hybrids.

Edited April 16, 2013 by hybridbear

[neod192]

Does regular CC limit how fast your car goes, or not? I'm pretty sure my Gti only allows a 5 mph variance from the set speed.

[acdii]

Does regular CC limit how fast your car goes, or not? I'm pretty sure my Gti only allows a 5 mph variance from the set speed.

Yes it does, it will apply braking to slow you down while in cruise. When I took my trip to FL I was going down the hills in TN and noticed that when the car slowed, the brake lights came on and I could see the light reflecting behind me. Same in the F150 except it downshifted.

[neod192]

Yes it does, it will apply braking to slow you down while in cruise. When I took my trip to FL I was going down the hills in TN and noticed that when the car slowed, the brake lights came on and I could see the light reflecting behind me. Same in the F150 except it downshifted.

So does hill assist just apply the brakes faster and limits the variance more than regular CC? Still not sure what hill assist really does!

[acdii]

I think hill assist is to keep the car from rolling backwards when stopped, but it could also be for going downgrade. I dont remember, does the shifter have an L?

[neod192]

I think hill assist is to keep the car from rolling backwards when stopped, but it could also be for going downgrade. I dont remember, does the shifter have an L?

Yeah, it stops it from rolling back for sure. The shifter does have an L.

[hybridbear]

So does hill assist just apply the brakes faster and limits the variance more than regular CC? Still not sure what hill assist really does!

 

Hill Assist is just what acdii says above.

 

The button on the shifter is Grade Assist. Grade Assist uses powerful regen to keep your speed from increasing at all. I saw Eco Cruise allow our speed to increase as much as 10 MPH going through the mountains when I didn't use Grade Assist. I often would leave the CC on but turn on Grade Assist as well and then the car would maintain its speed or increase no more than 1 or 2 MPH even on the steepest descents.

[hybridbear]

The shifter does have an L. I just created a thread about that http://fordfusionhybridforum.com/topic/6450-using-l-instead-of-d-for-faster-ice-warmup/

 

I think hill assist is to keep the car from rolling backwards when stopped, but it could also be for going downgrade. I dont remember, does the shifter have an L?

 

[milleron]

Hill Assist cannot be turned on & off. It senses when the car is on a hill and keeps the brakes applied for the second or two it takes you to move your foot from the brake pedal & get enough torque to keep the car from rolling backward -- especially important on cars in which the ICE may not be running.

Grade Assist can be turned off and on. It applies extra engine braking going down [steep] hills.

I think I"ve learned from this thread that Grade Assist differs from Low in that it won't actually slow the car on a downhill whereas Low certainly will slow you down, even going downhill.

I think that both Grade Assist and Low recharge the HVB faster than leaving the car in Drive.

Is this correct?

[corncobs]

Grade Assist will slow down the car! by recharging the HVB more aggressively.

If the HVB can't take anymore charge I believe the car operates like you have shifted into Low since the engine RPMs are really going up slowing the car down. In some cases down the Rockies the engine couldn't do it alone anymore so I helped out with the brakes.

[hybridbear]

The purpose of Grade Assist is to maintain your speed on a descent. It doesn't slow you down but rather maintains the speed you had when starting the descent. It works great in the mountains and even on small hills in the city or in parking ramps

[corncobs]

The purpose of Grade Assist is to maintain your speed on a descent. It doesn't slow you down but rather maintains the speed you had when starting the descent. It works great in the mountains and even on small hills in the city or in parking ramps

Correct but if you combine it with cruise control it will actually slow you down to hold / bring down the speed. I found this very helpful driving downhill for example the ECC would allow to go faster then the set speed but enabling grade assist prevents that and you stay at set speed even downhill.

[acdii]

When I drove through Denver last year in my F150, the cruise downshifted as needed to maintain speed going down those grades. It was pretty neat too, it climbed up in 6th gear with nary a whimper and coasted down in 4th. In the truck you can set the dash to show which gear it is in, so it was pretty cool watching the truck select the gears as needed. Never had to touch the brakes going down.