Here’s some trivia for you.

If you took all the drivers trading in hybrids and electric vehicles this year, what type of vehicle did about 22 percent of those folks end up buying in return?

If you said “a new SUV,” you’re correct.

This somewhat surprising statistic was shared recently by Edmunds.com, whose analysis illustrates an escalating movement away from these alternative-fuel vehicles to “gas-guzzling” rides, given the dip in fuel costs.

While more than a fifth of alt-fuel trade-ins are going towards SUV purchases this year, that figure was at just 11.9 percent in 2012, Edmunds said. In 2014, it was 18.8 percent.

One statistic that is perhaps even more surprising than the ones above is this one from Edmunds: after previously never dipping below 50 percent, alt-fuel loyalty rates (the percent of hybrid/EVs trade-ins going toward purchase of another alt-fuel vehicle) have fallen to 45 percent this year.

In 2012, that rate was over 60 percent.

“For better or worse, it looks like many hybrid and EV owners are driven more by financial motives rather than a responsibility to the environment,” says Edmunds.com director of industry analysis Jessica Caldwell.

“Three years ago, when gas was at near-record highs, it was a lot easier to rationalize the price premiums on alternative fuel vehicles,” she added. “But with today’s gas prices as low as they are, the math just doesn’t make a very compelling case.”

The scenario Caldwell describes plays into the challenges that electric vehicles, in particular, are finding in the used-car market.  In its latest Perspective report that delves into an “Electric Vehicle Retention Report Card,” NADA Used Car Guide pointed out a few factors at work.

“For the most part, used EV prices continue to be very soft, which really isn’t much of a departure from how prices have tracked over the past couple of years,” NADA UCG said in the report. “Used EV demand continues to be hampered by range and technology concerns, as well as by stiff competition from highly efficient — and more affordable — gasoline-powered cars.”

Certainly, when looking at retention rates for electric vehicles, there are some strong performers in the data set, particularly the luxury EVs, which have by and large beaten mainstream EVs in terms of holding on to their value, according to NADA Used Car Guide.

Additionally, the Tesla Model S is particularly strong. The Perspective report ranks 1-, 2-, and 3-year-old EV models by retention percentage, based on data from NADA Used Guide and ALG.

The Model S tops all three of those charts with respective scores of 83.1 percent, 71.1 percent and 57.2 percent**

Fuel Costs, Incentives & More 

NADA Used Car Guide’s report goes on to discuss the importance of gas prices and governmental incentives on the EV market, which it says cannot be overlooked.

Citing the latest data from the U.S. Energy Information Administration, the report says the average per-gallon cost of gasoline in April is $1.16 lower than a year ago.

“The fact that gasoline prices are more than $1 less per gallon than they were this time last year erodes demand for new and used EVs even further,” analysts said in Perspective. “Substantially lower gasoline prices make it even more difficult to justify an EV purchase from an economic standpoint. Lower gasoline prices combined with ongoing gains in gas-powered vehicle efficiency makes EVs an even harder sell.”

And it might not get much easier in the short term, with average gas prices expected to increase only modestly to $2.61 per gallon by the end of 2016, NADA Used Car Guide said, citing the EIA’s Short-Term Energy Outlook.

“As for encouragement, federal and state tax incentives have been an effective tool for sparking purchases of new EVs to counter the drawbacks potential consumers face,” NADA analysts said. “However, we’re beginning to see budget cuts and other issues which have legislatures reducing or eliminating incentives at the state level.”

The reduction in incentives was of several factors mentioned by Black Book’s Anil Goyal as having some impact on EVs. Goyal, the vice president of automotive valuation and analytics, and his team have observed “significantly lower prices” for electric vehicles (and some hybrids).

A great deal of that price crunch comes the fact there’s a good bit of supply flowing back into the used market, given how many EV sales were done as 24-month leases. Additionally, many consumers are eyeing potential longer-range vehicles that could be in the pipeline. Plus, there’s the whole incentive issue, which has impacted the supply side.

“Some of the supply that was driven into the market was due to the incentive. For example, in Georgia, we had a tax incentive, even on leasing of an electric vehicle, which is now taken away. But, it was very incentive driven, and then of course the gas prices had a good part to play in it,” Goyal said.

“So, as those gas prices have stabilized at a low level, and those incentives are starting to be questioned — at least at the state level — and we hear about newer products with longer-range coming into the market, I think that’s why there is that stress in pricing on those vehicles, with the supply coming back all at once.”

***Editor's Note: At the beginning of the Perspective report, NADA Used Car Guide explains the retention rate calculation as follows: We’ve provided retention figures for the most popular style level as determined by its share of new vehicle sales. While retention for other styles within a model lineup may be better or worse than the ones provided, the differences are generally small and do little to change the model’s overall standing in the used marketplace.

The retention calculation is a function of a three month average (March – May 2015) of NADA’s average trade-in value divided by a vehicle’s typically-equipped Manufacturer Suggested Retail Price (MSRP). Typically-equipped MSRP data was sourced from NADA Used Car Guide and ALG. Note that a vehicle’s rate of depreciation, and ultimately retention, is in part a product of the level of discounting at the time of new. As such, typically-equipped MSRP’s do not include any state or federal tax credits, nor do they include any manufacturer incentives or rebates available at the time of purchase.