GM says it's a good idea to drain the power out of the Volt battery pack if it's in a bad accident. That makes sense. After all, if a car is totaled one of the smart things to do is drain the gas tank. This bit of wisdom is one takeaway from an excellent article in The Economist that was written in response to some recent government tests that have caused Volt batteries to catch fire—after damaged batteries were allowed to sit for days or weeks.

Gas is dangerous because it contains so much energy—orders of magnitude more than you'd find in a battery pack. But its energy density is also why gasoline-powered cars can travel hundreds of miles on a fill-up, even though internal combustion engines are terribly inefficient, while electric vehicle owners have to fret about finding an outlet.

So, in a sense, what we really need are batteries that are more dangerous--at least in the sense that they store far more power than today's batteries--so we can travel long distances in an electric car. That would allow us to get rid of the really dangerous part of the Volt—the gasoline tank used to fuel its range extending generator.

According to the Wall Street Journal, it wasn't the battery cells inside the pack that caused the problem anyway.

GM engineers believe they can fix the battery and retrofit cars already on the road without an extensive redesign, people familiar with the situation said.

The company says a damaged coolant line is behind the problem.

In the crash tests, a break in the coolant line caused coolant to leak onto wiring in the battery. After time, the coolant crystallized, causing a short.

This might explain why the Nissan Leaf, which doesn't bother with coolant, hasn't had any trouble.

In 15 years, a new car that gets less than 50 miles per gallon could be considered a gas-guzzler--if new fuel economy regulations President Obama plans to announce tomorrow stick. Automakers have agreed to support the new standards, which would U.S. vehicles to average 54.5 miles per gallon by 2025. Current standards require an average fuel economy of 31.4 miles per gallon by 2016.

"If upheld, the plan would lead to the biggest gains in fuel economy since government began setting mileage regulations in the 1970s and could lead to substantial changes to the cars and trucks most Americans drive," according to the Wall Street Journal.

The impact of the fuel economy standards will depend on the details of the regulations. Previous fuel economy regulations have made exceptions for light trucks and SUVs, which helped lead to a boom in sales of these vehicles, cancelling out much of the reduction in fuel consumption provided by more efficient cars.

So far, it looks like that trucks will again receive special treatment. According to the Washington Post,

The White House originally pushed for a 56.2-mpg standard, but automakers demanded a carve-out for pickup trucks, which continue to rank among their top annual sellers. That provision lowered the average fuel efficiency gains to 54.5 mpg.

"...Until the White House provides us the full details, we are not in position to assess whether this is a strong proposal or whether there are any significant flaws," said Roland Hwang, transportation program director for the Natural Resources Defense Council. "From what we've read, there are certainly aspects that are encouraging but there are potential loopholes which could be troubling. Now it appears there is an agreement, it's time for the auto industry to work in good faith to not exploit the loopholes that threaten to undermine the consumer and pollution benefits."

One European automaker executive quoted by the Wall Street Journal suggest the rules may lead to the same problems seen in the past. "It's clearly inequitable and favors manufacturers of full size trucks," the executive said. "It could have an adverse effect on real world [gasoline] consumption by driving consumers to trucks."

One provision could lead to the standards being reduced before 2025. According to the Wall Street Journal: "In a key concession to auto makers, the White House also agreed to review the rules part way through the implementation cycle to determine if they are overly harsh or lenient given fuel prices, consumer behavior and technological advancements."

Details about how fuel economy can be assessed can influence what technologies will be adopted. In some standard driving tests, benefits of certain technologies don't show up.

The Washington Post reports that changes will be made to account for potential fuel savings from solar cells and thermoelectric devices, which supply electricity for running auxiliary systems and have an indirect effect on fuel consumption.

The Post didn't provide details about why the benefits of such systems aren't seen in current tests, but here's one guess: A solar cells might run fans that keep a car cool while it's parked. That would reduce air conditioning demand, and improve fuel economy, but that savings wouldn't necessarily be measured in test drives.

If we really wanted to decrease gas consumption, we'd push state and federal governments to make driving more expensive by doing things like increasing gas taxes and tolls on highways. That would force consumers to buy more-efficient cars, move closer to work, or even use public transit. But politicians know that these taxes and tolls are unpopular, so no matter how much sense they make, they tend to vote against them.

It just happened again, this time in Massachusetts. Faced with government spending that's far higher than what the commonwealth is taking in, legislators decided that they needed to increase taxes by about a billion dollars. But instead of raising them in a way that would actually do some good, legislators decided to increase the sales tax by 25 percent, according to the Boston Globe, while dismissing a proposal from the governor to increase gas taxes. The sales taxes will also stave off a proposed highway toll increase, which would have made it more expensive to drive.