A new study casts a different light on vehicles’ environmental effects. For the most energy-efficient vehicle—all things considered—you can’t do better than the Scion xB. That’s the word from a recent analysis of vehicles’ lifetime energy usage by CNW Market Research, an Oregon-based research group. Surprisingly, the Toyota Prius and other hybrids don’t look so environmentally friendly when viewed through CNW’s lens.

Researchers collected data on the energy usage of ’06 models from drawing board to scrapheap—or “Dust to Dust,” as the report’s title puts it. They included plant-to-dealer fuel costs, electricity used per pound of material, and hundreds of other factors, as well as more conventional and obvious measurements, such as fuel economy and emissions. CNW then translated the data into a simple number: lifetime energy cost per mile driven.

Under this analysis, the Scion xB had the lowest lifetime energy cost per mile at 49 cents. The rest of the top 10 included the Dodge Neon (64 cents), Chevrolet Tracker (67 cents), Saturn Ion (67 cents), Jeep Wrangler (70 cents), Toyota Corolla (72 cents), Chevrolet Aveo (74 cents), Hyundai Elantra (75 cents), Scion xA (76 cents) and Chevy S10 pickup (76 cents). By contrast, the Toyota Prius clocked in at slightly less than $2.87 per mile—only a little better than the industry average of $2.95. More costly manufacture, replacement and disposal of batteries, electric motors and other components contributed to the relatively high lifetime expense of this and other hybrids.

“If a consumer is concerned about family budgets or depleting oil supplies, it is perfectly logical to consider buying high fuel-economy vehicles,” says Art Spinella, CNW president. “But if the concern is of broader issues such as the environmental impact of energy usage, some high-mileage vehicles actually cost society more than conventional or even larger models over their lifetime.”