I wish I'd taken a picture. $1.99 per gallon gas at a station near me today. Cheap gas has had a number of positive benefits: It helps the economy, makes it easier for average folks to make their commutes and meet their bills and it sticks it to Big Oil.

But there are negatives as well. Electric car sales — nearly flat for 2015 — tend to suffer. And people not only drive more (vehicle miles traveled, or VMT, is up again), but they buy bigger cars and trucks. Small car sales are down, and the hot category for automakers is the crossover SUV.

nissan jukeThe Nissan Juke, recommended by Car and Driver, may be ugly but it gets 26 mpg in the city, 31 on the highway. Crossover mpg is improving. (Photo: Nissan)

According to Michael Sivak, a researcher at the University of Michigan's Transportation Research Institute, "After the average vehicle fuel economy [of the American fleet ] improved by 5.7 mpg from October 2007 to August of 2014 (from 20.1 mpg to 25.8 mpg), it decreased by 0.8 mpg through November of 2015 (to 25.0 mpg). The main culprit for the recent drop in fuel economy is the decreased price of gasoline."

The latter trends are also on the mind of Dan Becker, director of the Safe Climate Campaign. "Automakers are no longer improving mileage and emissions, threatening the success of the 54.5 mpg clean-car program," he told me. "The auto industry is exploiting the program's loopholes to boost gas-guzzler production and thwart the rules. They're making more SUVs, and other light trucks, than cars because trucks have weaker standards than cars, and more large vehicles because large vehicles have weaker standards than smaller vehicles."

Becker's conclusions are based on the latest Environmental Protection Agency "Trends" and "Compliance" reports, released this week. For 2014 model-year cars, the Trends report finds an average "real world" carbon dioxide emission rate of 366 grams per mile, "which is unchanged from model year 2013." We need these numbers to get continuously better if we're going to meet targets.

Chevrolet SparkThe tiny Chevrolet Spark, a nice ride with 39 mpg on the highway, is threatened by cheap gas. At $4 a gallon, people would be buying these in droves. (Photo: Chevrolet)

Of course, the EPA puts a nice spin on it all. New vehicle carbon emission rates, it said, "remain at the lowest ever recorded in the Trends database, and likely the lowest rate of all time." Meanwhile, new car fuel economy is "at the highest level ever recorded, and likely the highest of all time."

The Compliance report offers an optimistic projection from EPA. Some 26 percent of model year 2015 vehicles "already meet the model year 2018 CO2 emissions targets, or can meet them with the addition of expected air conditioning improvements." It added that 3 percent of 2015 production could even meet the 2025 CO2 targets — the holy grail.

Becker argues that this is compliance in name only. "While the auto industry may crow that it is technically in compliance, the bottom line is that automakers are no longer improving mileage and emissions. After all, cutting pollution is the real purpose of the rules. And automakers have stopped cutting pollution."

Cadillac EscaladeThe 2016 Cadillac Escalade: It still looks like a gas guzzler, and it still is one. (Photo: Cadillac)

There's a certain glass half-full, half-empty thing going on here. The Union of Concerned Scientists, which bows to no one in its concern about climate change, is encouraged by the progress. According to Dr. David Cooke, an analyst at the UCS clean vehicles program, the EPA reports "show that manufacturers are not just meeting, but exceeding, the emissions standards. Manufacturers are ahead of compliance for the third year in a row, and they’re exceeding the standards by the greatest margin to date."

But Cooke acknowledges the dark side. Consumers, he said, "are often choosing larger models, like SUVs and crossovers." But again, there's some light. Today's gas guzzlers, UCS notes, aren't quite as gas guzzly as they used to be. There's a 10 percent fuel efficiency improvement from five years ago, and "they're getting better every year."

Jeep Grand CherokeeGas guzzler No. 2, the Jeep Grand Cherokee. Go big with this one, and you're looking at 13 mpg around town. (Photo: Jeep)

I'm in-between here. I still don't like SUVs, and a 10 percent improvement isn't huge. Let's take a look at some popular models, why don't we? Buy the 2015 Jeep Grand Cherokee SRT8 4WD, and it will get 13 mpg in the city. 13! Highway is 19, for an average of 15. That's pretty pathetic.

Or how about a Cadillac Escalade ESV 4WD? Now we're at a mere 14 in the city, 20 on the highway and 16 combined. At $2 a gallon, owners aren't feeling the pain of those terrible numbers.

To be fair, it's the smaller crossovers that people are buying in bulk. But despite many technological gains — start-stop systems, direct injection, cylinder deactivation, small engine turbocharging — economy gains are erased when people opt out of small cars and into bigger ones.

Ultimately, we can do better than flat CO2 emissions. Here's a local TV report on $2 a gallon gas, from Massachusetts:

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.

The double-edged sword of cheap gas
Cheap gas may bolster spending, but it also drivers consumers to buy less fuel-efficient vehicles.