The Nissan Cube, which went on sale yesterday for a starting price of $13,990, will get an EPA-estimated 28/30 mpg city/highway with its continuously variable automatic transmission, Nissan spokesman Darryll Harrison said. With the base six-speed manual, mileage drops to 24/29 mpg. Firm mileage figures for the Cube had been hard to come by, with the only word from Nissan saying projected mileage would be “over 30 miles per gallon highway with the CVT” at the Cube’s unveiling last November.It didn’t quite make that, and we doubt Nissan’s marketers will make a big deal out of 30 mpg on the highway, especially considering some small hatchbacks easily rack up mid-30s highway figures. The good news is that city figure, especially considering the Cube’s urban-runabout pretentions. Put it this way: If you drive mostly city miles, the Cube is the most fuel-efficient box on wheels. Now, if only Nissan could do something about that swing-out tailgate.Mileage comparisons to the Scion xB and Kia Soul are below.

Automatic transmission:

• 2009 Nissan Cube: 28/30 mpg (29 combined)
• 2010 Kia Soul: 24/30 (26 combined)
• 2009 Scion xB: 22/28 mpg (24 combined)

Manual transmission:

• Kia Soul (1.6L): 26/31 mpg (28 combined)
• Nissan Cube: 24/29 mpg (26 combined)
• Kia Soul (2.0L): 24/30 mpg (26 combined)
• Scion xB: 22/28 mpg (24 combined)