You can trust people ... to change their minds. It must be crazy running a car company these days. Much as I’d love the private planes and executive dining rooms, I think being a CEO would drive me nuts, and nothing would be more vexing than trying to figure out what cars and trucks people will want to buy in a year or two. I’d probably greenlight an EcoCar mini, then watch it pile up in showrooms while my rival’s Mountain Conqueror SUV cleaned up.

Face it, Americans like big cars, SUVs and pickup trucks. For many, it’s the default purchase. The Honda Civic is more like the medicine you have to take. I’m told in an online post called “Why SUVs Suck and Why So Many People Buy SUVs” that our junk food diet is a big part of it. “Fat people don’t fit in small cars, so they demand larger cars such as SUVs to haul their big fat butts and junk around in.” So that’s why! It must have nothing with the wanderlust that is supposedly behind the American obsession with largely unnecessary four-wheel drive.

A foreigner posted this apparently sincere query: "Most people from other countries do not understand your prerogative on driving these big pick-up trucks and huge SUV's." The first response, "A lot of us are fat," was followed by a tongue-sticking-out emoticon. And it added, "Other than that, I really don't know why." Americans may simply be motivated to buy American, and if so here's a video for you, identifying which models actually are put together here:

The context for all this is a new survey from the Consumer Federation of America that says Americans really, really want to buy fuel-efficient cars. In a telephone poll of adult drivers, 88 percent said that the U.S. should reduce oil consumption, and the respondents who said it was “very important” want to see a five-mile-per-gallon improvement in their next car. Some 74 percent said that the new federal 54.5 mpg standard (by 2025) is a good idea.

Mark Cooper, director of research at the Consumer Federation, wants to think the best of his fellow citizens. He told me that the average car purchase today is three or four mpg better than it was a few years ago. To an extent, this is borne out by the facts. According to WardsAuto data, new cars bought in the first half of 2012 averaged 23.8 mpg, compared to 22.8 for the same period in 2011. This, the Energy Department says, as American households spent a record 2,850 annually for $3.53 average gas.

And, said Cooper, “Bigger cars today are going to be more fuel efficient. Trucks have improved more on a percentage basis than cars. And that’s fine from my point of view: If consumers want trucks they should be able to buy them, but they should also be better on gas.”

Cooper is a big supporter of the 54.5-mpg standard, which he says was the logical conclusion of George W. Bush saying that America is “addicted to oil.” And he says that people who buy greener cars like having more cash jingling around in their pockets. “They’re cash-flow positive in the first month,” he said. “If they buy efficiency, they want more of it.”

The flip side of this is that some new fuel economy tech will make cars cost more. The Center for Automotive Research (CAR), a nonprofit organization that sometimes has a bias toward the industry’s point of view, says that meeting the cost of the 54.5 mpg mandate will add $5,270 to the purchase price. It seems counter-intuitive that high prices would steer people to bigger cars — but that’s what’s kind of being implied here.

Unless, of course, people just don’t fit into the little car they bought, as our wise friend above has it. “Yes, we’re seeing some momentum back to the big vehicles,” Cooper admits. “But those big vehicles are going to get 45 mpg.” Maybe they’ll get there someday, but definitely not yet. See the grim truth by going to A 2013 Chevy Suburban 2500 with the 4WD that everybody has to have gets a combined 12 mpg. And don’t think you’re home free if you buy a Toyota — the ’12 Tundra pickup with a 5.7-liter V-8 and automatic (that's approximately it at right) averages 14 mpg.

The Big Three automakers did well in June — because big is back. The New York Times reported, “Detroit’s carmakers benefited from sales of their newest car models and a renewed interest in sport-utility vehicles.” Ford, for instance, despite a huge wave of new fuel-efficient compacts and subcompacts, saw sales up 7 percent, “with sport utility vehicles and trucks leading the way.”

What isn’t selling so hot for Ford? It’s smallest car, the Fiesta. Buyers prefer the larger Focus, in a 80/20 split. The Fiesta’s May sales were down 27 percent from the same month in 2011. That same ratio generally holds true industry-wide when comparing compact and subcompact sales. The bottom line seems to be that we will go smaller, but cast an envious eye at the behemoths in the next aisle.

MNN tease illustration: Shutterstock

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

What do America's car buyers want?
One day consumers are giving up their SUVs, and the next day they want them back. It's enough to drive an auto company CEO crazy. The bottom line: Watch what co