In honor of Earth Day, I will once again declare my love for my Chevy Volt electric vehicle. It has cool features, saves on gas, and yet still has that insurance policy of the “charge sustaining” engine for a total range that is unlike any other (except for maybe the Tesla). But yes, despite the engine as safety net, I will admit that “gas anxiety” is a real thing. I find myself avoiding the use of gasoline whenever I can, maximizing for electric even if it means altering routes or destinations.

Driving electric is a bit different than driving a regular automobile. Instead of “gallons in the tank”, EVs estimate “miles on the battery”. Since MPG on a Leaf or Tesla is a non-sequitur, the EPA has created an ‘MPGe’ measure for electric cars to provide some attempt at equivalence when comparing to gas. But MPGe and depletion of electric charge is not as linear and consistent as MPG would be in a conventional car.

You might find that 1 mile off the gauge while driving on flat land is more like 5 on the odometer, and coasting 1 mile downhill or with regenerative braking could measure out as 10 on the map. But EVs can’t violate the laws of physics – energy is conserved and the equation always balances. The flip-side to the “downhill economy” is that going uphill sucks juice like you wouldn’t believe. Freeway speeds also use more power than stop-and-go city driving, which is actually the inverse of conventional MPG ratings.

Noticing this, I occasionally – when time allows – take a more circuitous route to avoid going up hills, or a longer drive through town rather than hopping on the freeway. Despite the extra time and distance, I find that the eMiles don’t melt away quite as fast. To this end, my friend @cclaborne had an interesting idea. There should be a mapping app ala Google Maps or Waze that optimizes a trip route for EVs. Rather than picking routes based on speed or directness, it would instead consider elevation and road conditions. It would optimize for downhill and flatlanding, knowing that going around a hill might be better than cutting straight over. Such trip adjustments wouldn’t make a huge difference – maybe a few clicks here and there. But when every 2 miles off the tank means another hour on 8Amp charge to replace, every little bit helps.