We live in the mountains of NC and have now had the chance to do several mountain passes in the new van. Interesting observation: when cruise control is on and going down a long incline, once the traction battery is fully charged, the van will engine brake to maintain speed as opposed to engage the brakes. It really revs high to maintain speed and is quite noisy. Wonder why they would do this? Would seem to use more gas unless the Atkinson cycle motor has some way to cut fuel while engine braking.