Just got a '15 Volt for Wifey and so I don't drive it all that much. I am seeking info on the best driving mode for recharge one should use while in a long downhill. Here in West L.A. the I-405 South from the peak of the Santa Monica Mountains down to about Santa Monica Blvd. is a nice run, and I once got about 10 miles of charge. I recall that what helped was the heavy traffic (imagine that, in West L.A.!) allowing me to glide quite a bit. Also, is there only one rate of charging? Light vs. Hard braking? Downhill + braking? Fast downhill vs. slow downhill? If on an empty road where my low speed wouldn't annoy others, would L give more charge than D? Happy to save the earth AND some money! Thank you.