The 2008 Cars.com Mileage Challenge

As the price for a gallon of regular gas hovers above $3 a gallon — $3.40 in California — it’s high time we investigate what sort of mileage our cars achieve in the real world. In October, the EPA released its 2008 Fuel Economy Guide, which rates mileage using stricter standards for acceleration, air-conditioning use, cold weather and top speeds than were used in the past. The new measures purportedly reflect real-world driving better than before; MPG ratings dropped some 5 to 15 percent per car using the new standards.

Still, the EPA tests are done in laboratories, not on the road. To test real-world mileage, we took four cars across interstates and rural roads between Chicago and Madison, Wis., in October. Nine hours, two pit stops and one greasy lunch later, we had logged some 300 miles.

Naturally, our methodology was critical. We filled the tires at cold pressure to their recommended rates, began and ended the trip at the exact same gas pump, rotated drivers (and their weight) between all four cars throughout the trip, kept the windows shut and even logged how much A/C and cruise control each driver used. Otherwise, we drove as we normally would — and our editors run the gamut between lead-footers and geriatric-wannabes. The results are strictly unscientific, of course, but we think they reflect real-world driving.

Our cars included four 2008 models: a Nissan Rogue, Subaru WRX, Dodge Grand Caravan and Hyundai Sonata — a mix of body styles with manual, automatic and continuously variable automatic transmissions, two- and four-wheel drive, and four- and six-cylinder engines. Here are the full details, with the EPA’s 2008 ratings for each:

• 2008 Nissan Rogue S: AWD, 2.5-liter four-cylinder, CVT automatic; EPA gas mileage 21/26 mpg city/highway
• 2008 Subaru Impreza WRX sedan: AWD, 2.5-liter turbocharged four-cylinder, five-speed manual; EPA gas mileage 19/24 mpg city/highway
• 2008 Dodge Grand Caravan SXT: FWD, 3.8-liter V-6, six-speed automatic; EPA gas mileage 16/23 mpg city/highway
• 2008 Hyundai Sonata Limited: FWD, 2.4-liter four-cylinder, four-speed automatic; EPA gas mileage 21/30 mpg city/highway

Stay tuned for the results in our next post. We’ll offer a few tidbits in advance: Total driving time was just over seven hours, during which we averaged 43 mph. Any predictions on how we did? Drop us a line below.