We took six of the top-selling, most fuel-efficient cars in the U.S. and pitted them against each other. How’d they do in our mileage drive?
While Nissan's redesigned 2013 Altima may have the highest EPA-estimated mileage rating among family sedans, its trip computer had the largest discrepancy with our calculations at the pump. After a 185-mile loop, the Altima's trip computer read 4.38 mpg above our calculations — far higher than the variances we observed for the 2013 Ford Fusion, 2013 Honda Accord, 2013 Hyundai Sonata, 2013 Kia Optima and 2012 Toyota Camry. The Altima won the day's trip-computer mileage with an observed 35.9 mpg, but its calculated pump mileage — 31.52 mpg — landed it a third-place finish behind the Camry and Accord.
We took six contenders on a daylong mileage loop in mixed city/highway conditions. Per our usual mileage-challenge procedures, we began and ended at the same gas pump, swapped drivers over roughly equal chunks of seat time, kept windows and sunroofs closed and avoided cruise control. With cool temperatures and low humidity, we kept air conditioning off this time.
At day's end, our calculated pump mileage amounted to less than 1 mpg difference from what the trip computers read for five of the six cars, but the Altima's was off by 4.38 mpg. Why the discrepancy?