Alan Boyle / msnbc.com
A Chevy Volt tools down Interstate 5 with Mount Shasta in the background, as seen through the windshield of another Volt.
We're back on the road in a Chevy Volt, driving the second half of our 800-mile odyssey from Seattle to San Francisco — and that meant we were back on all-electric driving, at least for nine miles.
Our car was fully charged during the overnight stay in Medford, Ore., and usually that would give you 25 to 50 miles of gasoline-free travel. Chevrolet figures that most people drive less than 40 miles a day most of the time, and thus the Volt could plausibly go without using a drop of gas for days on end. Some have even talked about an issue with unused gasoline sitting in the tank so long that it goes stale. Turns out that the Volt has a special mode that will turn on the gasoline engine occasionally in that scenario, just to verify that the fuel lines are fresh and clean.
That wasn't a problem for us this morning. For one thing, the Chevy team had to upload masses of data about the car's performance so far, which drained the battery after its overnight charging. For another thing, we were heading into the Siskiyou Mountains of southern Oregon, and that meant we had to give up some of that low-cost electric rolling to provide hill-climbing oomph.
When the Volt goes up a steep grade, it draws electricity from the gasoline-powered generator, but even then, its performance can be a bit laggy. To increase the available power for the climb, extra juice comes from the batteries. But that means more of the battery power has to be held in reserve to start with. Normally, the Voltec drive train cuts over from batteries to gas-generated power when the battery reserve is drained to 20 percent of capacity. In mountain mode, that reserve is increased to 40 percent. But you have to hold onto that 40 percent to start with.
"That's why you have to put it in mountain mode 20 to 30 minutes before you hit a steep grade," Chevrolet Communications' Adam Denison told us. A lot of that power comes back during downhill costs, when the regenerative braking system captures electricity for the batteries. In fact, we were able to return to normal mode and resume all-electric driving after we went over Siskiyou Summit.
Mountain mode is the main reason why we drove for only 9.4 miles before the Volt's engine kicked in. That's got to be one of the shortest stretches of all-electric driving ever recorded with the Volt. One of the longest stretches was reported just this week, by AOL News auto writer Jeff Sabatini. He got 57 miles on the initial electric charge. But that's OK. He was probably driving on one of those sissy-boy roads in Michigan.
Follow msnbc.com's Alan Boyle and Jim Seida as they take an 800-mile "Electric Road Trip" in a Chevy Volt ... and file their dispatches from the road. Boyle is also tweeting about the trip as @b0yle on Twitter.