“Are you good?” asks my girlfriend. I nod, even though there’s just one mile of cruising range left. Wait, scratch that -- zero miles. “Are you sure?” she continues. I nod again, and then the gauge goes blank. About an hour after I ran the battery packs down and the range-extending engine switched on, the 2014 BMW i3’s two-gallon fuel tank has gone dry. Range anxiety in a range-extended EV, how about that?
This is an emergency
A range extender in an EV isn’t strictly speaking an emergency device, but it’s there mostly for emergencies. A little engine meekly churns and burns, and it sends a charge to the electric vehicle’s battery packs. So with a full charge, a full fuel tank, and some foresight, a range-extended EV will never leave you on the side of the road looking for an electrical outlet.
But what happens when your battery packs are drained, your fuel tank is empty, and you have hundreds of miles to go but no time for a charge? What happens when you need a range-extended electric vehicle with a 0.6-liter inline-two engine and a tiny gas tank to perform like a regular car? What happens when you have one afternoon to travel from Detroit to Chicago in a range-extended 2014 BMW i3?
Hipsters make velour cool again
Today, we look like well-off hipsters. My cat is standing on the back seats, poking her head out of my window, while my girlfriend and I are both wearing all-gray outfits that regrettably match. We’re badgering each other about obscure indie rock as we motor down the highway in this 2014 BMW i3, the hippest urban commuter you can buy.
The drive from Detroit to Chicago is a little less than 300 miles, and most cars make it without needing a top-off stop for the fuel tank. With a full charge and a full tank of gas, the BMW i3 says it has about 120 miles of combined range -- half from the batteries, half from the 38-hp, two-cylinder range-extender -- so it won’t make it even halfway before needing fuel.
We’re blissfully crawling through rush-hour traffic, gliding slowly and silently along in the slow lane. With its windows up, the i3 is crypt quiet (except for the obscure indie rock coming through the $800 Harman/Kardon audio system, of course). We can easily have a conversation, which is centered mostly around the i3’s eccentric and ecofriendly interior, as the dashboard is trimmed in open-pore eucalyptus wood, the wool cloth of the seat upholstery is trimmed in olive green leaf–tanned leather, and the floormats are velour.
Gone with the wind
I’m watching the i3’s electric-energy meter fall toward zero and waiting for the range extender to start up and break the silence we’ve been enjoying. The meter hits zero, and … nothing. Then the fuel gauge goes from 62 miles of range to 61 miles. I barely notice the range-extender engine as it comes to life, its soft hum blending seamlessly with the wind noise as traffic thins and the BMW gets up to cruising speed.
The car’s driving dynamics haven’t changed whatsoever, although I’m not quite sure why I thought they would, since the range extender has no mechanical connection to the driven wheels. I put my foot down, and the i3 smoothly shoots forward. (You never have to wait for a single-speed transmission to downshift.) The range-extended 2014 BMW i3 has narrow tires with 6-inch treads in front and 7-inch treads in the rear, yet it doesn’t wander aimlessly across the lane in search of traction and neither does it seem to be affected by light crosswinds. This EV is actually pretty nimble, which is not at all what I expected from a hatchback that’s 5 feet tall and wears bicycle tires.
“Paw, is dem aliens?!”
I guess men and women from the middle of Michigan don’t get out much, seeing as every rusty Pontiac Sunfire that passes us has a camouflage-clad person pasted to its passenger-side window and gawking at the i3 like it drove straight out of Area 51. My girlfriend and I are getting a kick out of it, so much so that I don’t notice how little fuel we have left. I go quiet, and she asks what’s wrong. “Well,” I say, “we’re out of gas.”
Past experience has taught me that a car with an “empty” fuel tank has about a tenth the range of a car with a full tank. (This is my theory, based only on my own flawed observations.) Let’s say you drive a Honda Civic with a cruising range of 350 miles. When the needle covers the “E” on the fuel gauge, I’d estimate you have about 35 miles before you’re screwed. So since we have a BMW i3 with a cruising range on gas of 62 miles, my theory suggest that we have an emergency cruising range of, like, 6 miles. At best.
Three fill-ups later
Spirited driving -- first up an off-ramp, then through a just-red stoplight, and finally through a parking lot to a gas station -- gets us to a fuel pump without stalling. I feed the BMW i3 just over two gallons of premium (which costs me $6), and pull back onto the road. We travel another 60-odd miles before filling up again, and then another 60-odd miles before filling up once more, and then finish the last leg to Chicago.
We arrive just after sunset, and I take a second to calculate our fuel economy for the trip. Factoring in one full charge and four full tanks of gas, we averaged 38 mpg. Not too shabby, considering I forced this carbon-fiber ute with a motorcycle engine and a whole mess of battery packs to go wholly outside of its comfort zone, which in turn forced me out of my comfort zone and caused me to have range anxiety in a range-extended EV.
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