That's how it used to be. But these days in lots of vehicles all the systems are very aware of each other, like how the HCH II holds the brakes on when you put take your foot off the brake to restart when auto-stopped on a hill. Even my Jeep'c cruise will shift down the auto trans to help hold a setting on hills. All the lux manufacturers have adaptive cruise control now that will let the cruise drive in stop-and-go traffic (using radar, gas, brakes, and trans to maintain a max speed and maintain a safe distance from the car ahead, even bringing the car to a stop for lights and accelerating it away afterward).

Obviously, we don't have those systems in the HCH. But the ICE, IMA, CVT, and brakes all talk to each other in every other situation the car's in, so there's no reason to think they can't modulate the cruise the same way.

I just finished a trip from Salt Lake to northeast Montana and back, several 6-8 percent mountain passes on the trip. The cruise *always* held its setting without ever going more than a mph over. I couldn't quite tell how, but I saw a few times that in fact even with 8-bar SOC, the charge/assist indicator was still showing 5-7 bars of charging. I don't know where the electricity was going (maybe my SOC meter needs to reset?), but there was plenty of engine braking. I didn't ever feel it put on the brakes.

But I would second toast's thinking that the engine computer could also simply open the valves back up to let the ICE brake with almost zero fuel consumption (which is what every other ICE in the world does when it's engine-braking: the engine brakes because it has to compress the air in the cylinder but there's only idle-level fuel so no power is created). We -- or Harold's wife -- wouldn't notice much effect on a high-percent grade because 1.3 liters just can't give you enough compression-resistance to hold back 3,000 pounds. When an HCH engine-brakes, it's pretty much all generator drag.

btw, holding 82-83 on interstates in the mountains (I wanted to see whether it would do it), average FE 43 mpg. I was happy.

-doug

 

82-83 mph through the Rockies? And 43 mpg? Amazing! (So now that you know you can do it, back to slower speeds? ) I've done a few trips from OH to MD on I-70 and I-68 (through the baby mountains) and usually go about 60-65 mph, and get a little over 50 mpg. I am hoping that the fact I have less than 2500 miles on my car is the reason why its only about 50 for such "low" speeds.

I have been in several situations where my charge bar is maxed out going down some grades, but I don't use cruise at all. Cruise likes to throttle up the RPMs a lot higher than I like on the up slopes!

 

My wife never uses cruise! On the hill she was complaining about, it would be imposible anyway because of the hair-pin corners! Maybe that is why I have never noticed this to br a problem, I allways use cruise. I haven't gone down that hill however. Thanks for the comments,H

 

I drove the same hyway that my wife did and had no problems. The car handles great! It does not help to shift down to drive two. I used my breaks when nessasary. No differant than ay other car.