When it comes to electric cars, conventional wisdom states that sales will inevitably decrease alongside gas prices.
After all, the argument goes, if buyers can't expect to save as much by cutting fuel costs, they'll be less inclined to buy a plug-in, right?
Not exactly. In fact, not at all: The conventional wisdom is simply wrong.
Many more factors influence the decision to buy an electric car than gas prices at any given moment.
Now that significant sales data from the current period of low gas prices is available, that's becoming more apparent.
2015 Nissan Leaf
After examining several studies of 2014 and early 2015 car sales, the Los Angeles Times concluded that falling gas prices don't flatten sales of green cars in a recent report.
Carlypso--a firm that facilitates private-party sales of used cars--noted a 10-percent uptick in sales of new trucks between December 2013 and June 2014.
However, it was quick to note that this occurred before the major drop in gas prices.
Meanwhile, sales of plug-in electric cars rose 3 percent in January 2015 compared to the same time last year.
2014 Chevrolet Volt
Between May and August 2014--around the same time trucks sales rose and just before gas prices plummeted--electric-car sales rose steadily, according to the Electric Drive Transportation Association Trade Group.
The only area where low gas prices seem to push buyers toward less-efficient vehicles is used cars.
Research firm iseecars.com found that when average gas prices dropped from $3.90 per gallon to $2.90, used truck sales increased 2 percent.
A comparable $1 increase in gas prices saw a shift back to passenger cars.
Given that roughly 280,000 battery-electric and plug-in hybrid just over 100,000 electric cars were sold in the U.S. over the past four years--a tiny fraction of the millions of new cars sold every year--it's worth noting that there aren't many used examples available.
Tesla Model S electric-car road trip, upstate New York to southern California [photo: David Noland]
But wait, there's more.
Another study--from electric-car advocacy group Plug-In America--found no correlation between gas prices and electric-car sales at all.
From December 2010--when the Chevrolet Volt and Nissan Leaf first went on sale--to November 2014, the study found that electric-car sales steadily increased, while gas prices rose and fell erratically.
These studies show what becomes apparent to all of us when we walk into a showroom to buy a car: that decisions aren't governed by one overriding factor.
After all, gas prices change almost constantly, but people have to live with the cars they buy for years.