The internet abounds with stories of mpg-obsessed drivers that have managed to squeeze fuel efficiency well beyond the initial capabilities of their cars, like gas-sipping camels crossing the desert on half a water bottle.

But even with those tales of success, and recent improvements made by automakers, it’s hard to envision an uber-eco production car that isn’t plastered with solar panels or shaped like an egg with a tail. Gas prices continue to fluctuate and the race for efficiency is heating up in the face of government mandates, but one question remains unanswered.

How long before a 100mpg car reaches production?

Of all the aspects that determine a car’s overall MPG, weight, aerodynamics and engine efficiency are three of the most important. If the car is too heavy, it takes a lot of work to gain speed. If the car is constantly fighting the wind, same story. If the engine doesn’t make good use of the energy it produces, you might as well just move into a gas station. More...

Owning an Electric Vehicle could save drivers between $750 and $1,200 per year at the pump, according to a new study released this week by the Union of Concerned Scientists. The report says that driving an EV is certainly more environmentally-friendly and less costly than driving either a hybrid or a gas-powered car. It also found that the car's emissions and value can vary depending on region.

As automakers continue to experiment with Electric Vehicles and other high-efficiency models, and gas prices have recently risen to nearly $5 per gallon in some parts of the country, interest in green driving is at an all-time high. President Obama has pushed for high-efficiency mandates and called for 1 million plug-in hybrid cars on the roads by 2015.

But what kind of efficient vehicle makes the most sense? Should you go with an electric, hybrid, or one of the higher MPG gas-powered cars? More...

Recommendations for dramatically increased fuel economy over the next decade and beyond have garnered considerable attention. Currently, the rules call for a 35.5 mpg Corporate Average Fuel Economy (CAFE) requirement by the 2016 model year. The big question is: What then? Proposals for gas-mileage targets ranging from 47 to 62 mpg have been stated, to take effect no later than 2025. Will fuel savings offset the higher cost of such a fuel-efficient vehicle?

A recent study by the Center for Automotive Research found that with a 62-mpg standard, the amount that a motorist would save in gasoline over a five-year period would not exceed the increased cost of the complying vehicle. As a result, the 62-mpg requirement favored by environmentalists would not be cost-effective. In contrast, several of the less dramatic CAFE targets (47, 51, or 56 mpg) would result in fuel savings that exceeded the increased cost of an average vehicle.

The Obama Administration has put forth a preliminary proposal for increased CAFE standards in 2025, but a specific figure has not yet been stated. Automakers claim the situation deserves more study–but that’s generally a euphemism for outright opposition. More...

Gasoline and diesel don’t normally mix––try putting the wrong one in your tank and you’ll find out––but Chrysler is working on an engine that burns both simultaneously to achieve high performance and high fuel mileage.

Working with the Department of Energy, Chrysler is developing a twin-turbocharged, high-compression gasoline engine that injects diesel into the combustion chamber to control preignition. This allows the engine to have a higher compression ratio than would be possible using just gasoline.

Chrysler says this new engine will have performance comparable to that of its 2009 4.0-liter V-6, but with 25 percent better fuel mileage. But while the theory is appealing, it remains to be seen whether drivers will take to filling up twice at every fuel stop. And how is that added fuel economy affected if they drive faster everywhere to make up for the time they lost filling up?

Plenty of politically-tinged issues are guaranteed to elicit arguments these days. One of them is gas mileage for future vehicles. High-mpg proposals might not be the most crucial matters on the agendas of President Obama and the U.S. Congress, but advocates on each side can be just as vociferous as those who take partisan stances on countless other legislative proposals.

The number that’s been tossed about the most is 62 mpg, as a goal for average fleet fuel economy by the year 2025. That amounts to about a 6-percent increase per year. Several other proposals have reached the White House, asking for as little as a 3-percent yearly improvement (to about 47 mpg). Currently, the plan for Corporate Average Fuel Economy (CAFÉ) is an average of 35 miles per gallon, by 2016.

In a survey conducted for the Consumer Federation of America (CFA), 62 percent of respondents said they supported mandating a strict increase, to 60 mpg.

The Alliance of Automobile Manufacturers quickly reacted in opposition, asking President Obama to scuttle such a proposal pending further study of its impact on auto safety, car sales, and jobs. Former GM vice-chairman Robert Lutz also stepped into the fray. According to autoblog.com, Lutz told reporters that “nobody knows how to do a full-line fleet with the equivalent of 42 miles per gallon.” (Lutz was referring to a less-stringent mileage proposal.) More...

America’s most notable gasoline shortage seems like ancient history now, not only to drivers who were not yet born, but even to those of us who were adults in 1973-74. Now, with fuel prices rising rapidly, instability growing in the Middle East and North Africa, and controversy over oil-drilling escalating, a quick look at past crises might be prudent.

Only once has rationing ever become law, and that was during World War II. Through the postwar years, Americans grew accustomed to cheap gas. Few gave a thought to any possible limits to its availability, so the reaction to the 1973-74 crisis came as a shock to nearly everyone.

When the shortages began in 1973, resulting from an embargo on oil supplied by Arab nations through the Organization of Petroleum Exporting Countries (OPEC), gas stations in many areas soon ran completely out of fuel. Those who still had some saw immense lines of cars waiting to get to the pumps.

As early as May 1973, Senator Henry “Scoop” Jackson (D-Washington) had proposed a rationing plan. By November, the last of the Arabian oil arrived in the U.S.

President Nixon resisted pressure to establish a standby rationing plan. Even so, the Office of Management and Budget devised several tentative plans, which might have involved issuance of authorization cards, along with coupons that would be good for a specified number of gallons.

Early in 1974, the Nixon Administration did propose a contingency rationing plan. Coupons were printed in January, but they weren’t needed. The OPEC embargo was lifted, and the prospect for rationing disappeared as fuel became more readily available again.

When the second gasoline crisis erupted in 1979, President Carter’s Administration came up with a potential rationing plan, to take effect when the shortage reached a predetermined level. That crisis eased before any such plan was needed, and the prospect for rationing was shelved again.

Most of us think little about that part of the past. Fuel is a big issue nowadays, but the concern is far more about price than any prospect of shortages–whether real or created.

Yet, we’re dealing with oil supplies from an increasingly volatile and politically unstable part of the world, with insurrections and revolts against harsh dictators and despots likely to increase rather than ease. OPEC might not be the likely culprit for a modern-day curtailment of supply, but other routes could lead to that outcome. Keeping our heads in the sand about the possibility could be asking for another harsh surprise one of these days.

Also read, "Protecting Yourself While at the Pump, and other Drive Smart articles.