What follows is the list of the most fuel efficient vehicles as listed by the Environmental Protection Agency. No surprise, but for the 2011 model year the most fuel efficient vehicles was the new Nissan Leaf plug-in, while the gas-electric hybrids round out the list.
| Brand (EPA Rated- 2011) | City Economy | Highway Economy |
| 2011 Nissan Leaf, Electric Vehicle, Auto (A1) | City 106 | Highway 92 |
| 2011 smart fortwo cabriolet, Electric Vehicle, Auto (A1) | City 94 | Highway 79 |
| 2011 smart fortwo coupe, Electric Vehicle, Auto (A1) | City 94 | Highway 79 |
| 2011 Chevrolet Volt, 4 cyl, 1.4 L, Auto (variable gear ratios), Premium, PHEV | City 35 | Highway 40 |
| 2011 Toyota Prius, 4 cyl, 1.8 L, Automatic (variable gear ratios), Regular | City 51 | Highway 48 |
| 2011 Lexus CT 200h, 4 cyl, 1.8 L, Automatic (variable gear ratios), Regular | City 43 | Highway 40 |
| 2011 Ford Fusion Hybrid FWD, 4 cyl, 2.5 L, Automatic (variable gear ratios), Regular | City 41 | Highway 36 |
| 2011 Mercury Milan Hybrid FWD, 4 cyl, 2.5 L, Automatic (variable gear ratios), Regular | City 41 | Highway 36 |
| 2011 Lincoln MKZ Hybrid FWD, 4 cyl, 2.5 L, Automatic (variable gear ratios), Regular | City 41 | Highway 36 |
| 2011 Honda Civic Hybrid, 4 cyl, 1.3 L, Automatic (variable gear ratios), Regular | City 40 | Highway 43 |
| 2011 Honda Insight Hybrid, 4 cyl, 1.3 L, Auto (variable gear ratios & AV-S7), Regular | City 40 | Highway 43 |
| 2011 Hyundai Sonata Hybrid, 4 cyl, 2.4 L, Auto(6-spd), Regular | City 35 | Highway 40 |
| 2011 Honda CR-Z, 4 cyl, 1.5 L, Auto(AV-S7), Regular | City 35 | Highway 39 |
| 2011 Lexus HS 250h, 4 cyl, 2.4 L, Automatic (variable gear ratios), Regular | City 35 | Highway 34 |
| Brand (EPA Rated – All Years) | ||
| Honda Insight Model Year 2000 | Combined 53 | |
| Toyota Prius Model Years 2010-2011 | Combined 50 | |
| Chevrolet Sprint ER Model Year 1986 | Combined 48 | |
| Geo Metro XFI Model Years 1990-1994 | Combined 47 | |
| Honda Civic CRX HF Model Years 1986-1987 | Combined 46 | |
| Honda Civic HB VX Model Years 1994-1995 | Combined 43 | |
| Honda Civic Hybrid Model Years 2006-2010 | Combined 42 | |
| Honda Insight Model Years 2010-2011 | Combined 41 | |
| Toyota Prius Model Years 2001-2003 | Combined 41 | |
| Chevrolet Sprint Model Year 1989 | Combined 41 | |
| Suzuki Swift Model Year 1989 | Combined 41 |