Photo courtesy of Nissan

 Nissan still calls its Quest a minivan. But there is nothing “mini” about it. The 2012 Nissan Quest LE driven for this column is more like a bus, an expansion of size variously attributed to the widening girths, populations and egos found in the North American markets in which it is sold.

No offense is intended here.

Choose any available medical report on weight and obesity, including the latest (May 2012) by the National Academy of Sciences’ Institute of Medicine. Succinctly stated, the findings are that Americans are fat and getting fatter — nearly two-thirds of adults and one-third of all children in the United States are overweight or obese. By 2030, the institute, a collection of 65 of the nation’s most esteemed medical doctors and health research scientists, estimates that 42 percent of the nation’s citizenry will be overweight or obese.

That’s a lot of weight. It is affecting health costs in the United States and Canada — an estimated $300 million annually for weight-related diseases. It also affects the size and fuel economy of the vehicles we drive.

It’s simple. You don’t develop sardine cans to transport whales.

The Nissan Quest bus is a case in point. The first generation of that vehicle entered the United States in 1993 as a joint-venture product between Nissan and Ford Motor Co., sold as the Mercury Villager. It was a smallish thing, a minivan in the truest sense of the word, although capable of carrying seven people with some deft maneuvering of cabin seats. It barely stretched 16 feet in length. It had a curb weight, poundage minus passengers and cargo, of 3,815 pounds. It was narrow, urban-maneuverable and, with the exception of several long-ago-corrected defects, an ideal people hauler for a small-to-moderate-size urban American family.

We’re now in its fourth generation. You can be pardoned for not recognizing the thing. It’s big — nearly 17 feet long, 6.5 feet wide and 6 feet high. Step-in height is 15.7 inches to 16.1 inches, depending on whether you choose 16-inch-diameter or 18-inch-diameter wheels. (Hint: You get slightly better fuel economy with the smaller wheels, but you get better handling and ride with the bigger ones.)

The new Quest LE, the top of the Nissan Quest line, weighs in at 4,658 pounds — a large portion of that weight attributed to a super-tufted, amenity-laden vehicle with motorized, automatic everything — power sliding side doors, power automatic rear hatch, power seats and glass roof, and electronic infotainment and connection systems. Meet the bus/minivan as motorized castle.

Why all of those changes? It all depends on who you listen to at Nissan. But the best answer can be found in a distillation of those heard around the global car industry.

First, the new Quest is based on the platform of the Nissan Elgrand — a tall front-wheel-drive luxury minivan sold by Nissan in Japan, China and Thailand. Those Asian markets are becoming the largest retail zones for Nissan and many of its rivals, meaning that vehicle platforms developed for those markets are likely to be used in the still-lucrative North American arena to save development and production costs.

Quest modifications for North America required a widening of the body, by about five inches, to reduce the high, narrow appearance of the Elgrand, which makes sense on narrow streets in countries such as Japan but might seem ought of place in American West and Midwest.

Finally, much of the new Quest’s larger size is attributable to MWS (McDonald’s-Wendy’s Syndrome). Car manufacturers and marketers aren’t stupid. They work with whole corporate divisions dedicated to researching what is happening to the American body and psyche. Scientists say that the body is getting fatter and that large and potentially profitable segments of the mind is indulging itself in a profound sense of entitlement — more space, more stuff, more power, and more fuel economy . . . if possible.

The new Quest LE comes through with more space, stuff and power. But with best-guess federal fuel-economy numbers of 19 miles per gallon in the city and 24 on the highway, it still has a way to go in the mileage marathon.

In its fourth-generation presentation, the Nissan Quest has become something of a niche vehicle — big and rich enough to please and service affluent, well-fed large families, but much too big to make sense for daily urban commuting for one or two people or a small family of three or four more interested in fuel economy and parking ease than in prestige or clan-carrying ability.

The new Quest LE is no easy piece of work when it comes to driving. It has one of the world’s best V-6 engines (3.5 liters, 24 valves, 260 horsepower and 240 foot-pounds of torque). But that engine is linked to a sometimes iffy continuously variable transmission (no fixed gears). It is also pulling lots of weight.

I’m not terribly sorry to see this one go back to the manufacturer. But I’ll mute my criticism because we’re facing a long summer in the Brown household. We have relatives aplenty. They like to visit. Whenever they come here, they expect local and regional transportation in a motorized leviathan with a super-cushy ride. The new Nissan Quest LE fits that bill perfectly.