2011 Chevy Volt: Propulsion Power is Reduced
July 20, 2011
To Mountain Mode or not to Mountain Mode, that is the question. The Volt's Mountain Mode essentially stores up electricity so that you can apparently climb any grade in the United States at 70 mph. Trouble is, it hurts your electric range (should you be in electric-only mode) or your fuel economy. This was my quandery last week during leg 1 of the Fuel-Sipper Smackdown.
As this was a fuel economy test, I decided to leave the Volt in Normal. Even with the plug-in electric charge depleted, the powertrain had no trouble getting up the rather steep Cajon Pass on Interstate 15. Other grades were dispatched without issue, including one ascending Panamint Valley. However, as I made the long climb up the mountain leading into Death Valley, the Volt doth protested.
As the above photo shows, I got a warning saying "Propulsion Power is Reduced," and my speed quickly declined. By this time it was too late to engage Mountain Mode. Eventually, I had my foot planted to the floor, the engine was whirring like a lawn mower and the Volt was dawdling up the mountain at an embarrasing 35 mph. The other fuel-sipper cars formed a parade behind me, wondering why I decided to drive like Ma and Pa RV Owner.
Had this not been a fuel economy test, I almost certainly would've seen the big scary mountain ahead and gone "duh, Mountain Mode." But at least I now have a good idea of the rather extreme circumstances in which the Volt's gasoline engine is overwhelmed when in Normal Mode. (There's also the matter of whether drivers will even know there's a Mountain Mode there).
So how did fuel economy fair in this scenario? Curiously, the Volt still managed to achieve 39 mpg (subtracting its E range) on this more vigorous portion of the Death Valley leg, whereas it only managed 31 on the less mountainous second portion. I have no idea why. Beyond Fuel-Sipping, Death Valley was definitely an interesting test for the Volt.
For more fuel economy numbers from Fuel-Sipper Smackdown 4, you'll have to wait a few weeks, however. Stay tuned, but at the very least I can say I once again walked away impressed with this nifty car.
James Riswick, Automotive Editor @ 7,799 miles