As longtime readers know, Jenelle bought an all-electric Chevy Bolt a couple of years ago. We’ve driven it about 18,000 miles. It replaced a Buick SUV that had about 85,000 miles on it. The total cost of the Bolt out of pocket, after the trade-in and the electric-vehicle rebate, plus the cost of adding a 240-volt (Level 2) charger to our garage, was about $25,000.

The Buick got about 20 mpg, so we’ve saved 900 gallons of gas. Gas has been around $4 a gallon here for most of that time, so that represents a savings of $3,600. The onboard meter has been reporting that the Bolt gets about 3.5 mile...