The maximum fuel range you see advertised on TV can be a myth.
Technically, the claimed range is accurate if you squeeze every last drop of fuel from the tank and are able to achieve a sometimes optimistic highway mileage. Doing so can also lead to standing on the side of the road after running out of fuel and discovering how acclimated the local wildlife is to humans.
The diesel-powered 2013 Volkswagen Passat TDI has a massive advertised range of 795 miles, marked by a footnote reading, “Range based on 43 mpg highway EPA estimate and 18.5-gallon fuel tank for 2012 2.0L TDI, manual transmission. Your mileage will vary.” There's even a humorous ad about two guys learning Spanish on a road trip in the time it takes to run out of fuel in the Passat.
That 795-mile number is big. To give it some perspective, the distance from Chicago to Washington, D.C., is roughly 700 miles. It also happened to be the trip I used to test the Volkswagen Passat TDI’s range.
We know it’s "possible" to exceed the TDI’s range estimates based on a 1,526.6 trip one fuel-friendly couple took in a Passat TDI. However, my plan wasn’t to drive with hypermiling techniques, boost tire pressure above the factory recommendations or alter the car in any way for better mileage. I merged onto the expressway, set the cruise control to 70 mph and was on my merry way.
Letting the cruise control do the work resulted in a stunning 52.5 mpg average over the combined 1,452-mile trip. By the end of each leg, the seemingly endless 18.5-gallon tank wasn’t remotely close to being empty; there was an additional 130 miles of range left after my return trip.
The journey wasn’t totally uneventful. My troubles revolved around filling up. Finding a station that sold diesel and then finding diesel that complied with the Passat’s warranty requirements proved difficult. The nearest diesel pump in Chicago had a warning stating the fuel could be 5-20% biodiesel, and the amount cannot be verified because the diesel wasn’t their branded fuel. The Passat TDI recommends a maximum 5% biodiesel blend to honor the warranty.
Finding diesel in an unfamiliar city also proved annoying until I downloaded Diesel Power magazine’s fuel-finder for the iPhone, a free application and invaluable addition to my trip. Unfortunately, the pump I filled up at didn’t click off automatically — apparently not uncommon with diesel pumps. The few gallons of diesel that spewed onto the ground before I realized what happened ruined my fill-up calculations for the first leg and added cost to the fill up. That station — unlike the second one I filled-up at — didn’t have plastic gloves to use while filling up, so my hands were oily and smelled like diesel after I frantically pulled the nozzle from the tank.
Even with the overfill, the trip’s combined cost of fuel totaled a paltry $140.60. That’s a fraction of what I would have spent to fly two people from Chicago to D.C. Even the additional $80 I spent in round-trip tolls makes driving the Passat TDI to D.C. reasonable. If I had gotten the best highway mileage of the gas-powered 2.5-liter Passat base trim — rated at 31 mpg highway — it would have tallied a higher cost overall even with the lower price per gallon of regular unleaded.
Granted, the trip took a combined 23.4 hours of driving time, but it was a scenic drive through Illinois, Indiana, Ohio, southern Pennsylvania and Maryland. Plus, the Passat is an amazing road tripper with a level of seating comfort and quietness that made the drive painless.
Chicago to DC
Time: 11 hours, 32 minutes
Trip computer mpg: 53.8 mpg
Fill-up calculation: NA from tank spillage
Trip miles: 713.1 miles
Average speed: 62 mph
Outside temp.: 74 degrees
DC to Chicago
Time: 12 hours, 9 minutes
Trip computer mpg: 51.2 mpg
Fill-up calculation: 51.7 mpg
Trip miles: 738.8 miles
Average speed: 61 mph
Outside temp.: 63 degrees