Driving until empty in a 2013 Volkswagen Passat TDI

By Christopher A. Sawyer
The Virtual Driver

(November 3, 2013) The idea was simple: Borrow a Passat TDI from the folks at Volkswagen, and see just how far you can reasonably expect go on a single tank of gas. Aware that this trip meant driving from the suburbs of Detroit to Clifton, Va. — not far from VW’s U.S. headquarters in Reston, Va. — it shook loose a top of the line, Tungsten Silver SEL-level model. Yes, we’d be traveling in comfort, but it would be a car that was not the lightest in the Passat TDI lineup.

Other than the fuel used traveling from the filling station to the house and a bit of running around town, the tank was full. So was the interior. Once again, we’d be heading to the girlfriend’s sister’s place, bringing a number of things collected over the intervening months.

The trunk and (folded) rear seat were full. My rule of thumb calculations suggested it was equivalent to having two full-size adults and luggage for four in the back; exactly the opposite of the way the car was tested by the EPA when it gave the Passat TDI a mileage rating of 30 city/40 highway/34 combined.

When it comes to diesel powerplants, the EPA numbers are bit misleading. This may come as a shock to those who still believe in the Tooth Fairy, expect the Affordable Care Act to be affordable, and otherwise accept the lies others tell them. However, the official mileage ratings underestimate the fuel economy of diesels (and overestimate those of hybrids) due to the peculiarities of the test protocol. So, again by rule of thumb, I expected to hit these numbers, if not slightly exceed them.

Starting later than normal — that is, the sun was up and the birds had already had their morning coffee — we headed south toward Ohio before turning east and heading for the coast.

The day we left is easy to remember as it was the Monday after Clint Bowyer’s ham-handed “spin” that momentarily got Martin Truex into The Chase and set off a firestorm of controversy and acid indigestion for NASCAR. Rather than listen to the various music stations on the SiriusXM satellite radio, my front seat passenger, girlfriend and former motorsport editor at AutoWeek magazine (all the same person for those of you with ADD) tuned into NASCAR Radio and listened with glee as the story unfolded.

I won’t repeat what she said about Michael Waltrip Racing — and Michael Waltrip in particular — if only to prevent you from getting the wrong impression. Usually she doesn’t swear like a sailor.

We could have blown past the rest stop on the Ohio Turnpike where we make our usual first stop for fuel, but nature called. Heck, the gauge said we had
nearly 7/8 of a tank of fuel left, and about 650 miles to empty. Fuel was not the problem. In fact, it wasn’t a problem all the way to Clifton and part of the way back. The fuel gauge seemed to move more slowly than the sun in the western sky, while the average mpg on the trip computer continued to rise.

We started the trip with an average of 36 mpg showing on the trip computer. This quickly started to climb as we started our freeway cruise, and leveled off at 45 mpg; hitting a high of 47 mpg for a long stretch in Maryland. The miles to empty increased as this happened, each highway mile adding distance as the average miles per gallon increased. As we traveled further, we noticed that we were not the only Passat on the road.

It appears that turnpikes are a favorite stomping ground of these American-built German four-door sedans. Each car was heading east with us, usually at an even higher rate of speed, and carried license plates from states like Pennsylvania, New York and New Jersey. Only once did we see a Passat that wasn’t a diesel, and that model was a full-tilt 3.6-liter V6 seemingly on a low elapsed time run back to home base in North Carolina.

We understood immediately why the Passat was so popular with these drivers: it is quiet, comfortable, roomy and does not provide these positive attributes by being mind-numbingly dull and lifeless. Granted, you won’t mistake the Passat for a 5 Series or E-Class. However, you also won’t feel like you’ve found a modern-day equivalent of a Buick 225 in its glitzy, Novocain-numb glory.

One reason is the front compartment, which is conservatively handsome, with easy to decipher switches and gauges, great sightlines and comfortable seat
s. Rear seat passengers get tons of leg room, good hip and shoulder room and similarly supportive and comfortable seats. Plus, there’s the bonus of a split-fold seatback that allows you to pile an enormous load of stuff in the back; things like big outdoor Chinese-style lamps found at an estate sale, five 6-foot folding tables, luggage, large ceramic flower pots and much, much more.

Despite the weighty contents of the trunk and rear cabin, the turbocharged diesel engine, though only 2.0-liters in displacement, handled the load. It’s not the 140 horsepower that’s important, you use it to maintain speed more than anything. Rather it’s the 236 lb-ft of torque that’s in full bloom from 1,750 rpm.

Unlike a gasoline engine, a diesel doesn’t, and doesn’t need to, reach the upper rev ranges in order to move proceedings along. It uses grunt — tor
que, the force that gets everything moving — to get the Passat TDI’s nearly 3,500 lb. off the line and keep it accelerating. When you have no need for quick acceleration, you can feather the throttle and drive the car on small amounts of boost, which improves fuel economy.

We rolled into Clifton that afternoon with just under 5/16 of a tank left, 210 miles on the distance to empty readout, and the average mpg number up to 48.2. Three days later, we headed back home, stopping to refuel in Frederick, Md., only because we weren’t sure if there would be traffic between there and the next stop in Breezewood, Pa. As it turned out, there wasn’t. We could have made it on fuel we had in the tank, though I would have wanted a small container of diesel onboard just in case.

The refueling stop put 13.5 gallons into the tank at a price per gallon of $3.99, and a total of $54.11. Our average mileage was a stout 46.0 mpg, well above the 40 mpg highway rating. With the full 18.5-gallon allotment onboard, we breezed back to the Detroit suburbs, getting a slightly lower 45.5 mpg for the return trip headed into the wind.

The biggest blot on the ride home was that the SiriusXM subscription lapsed while we were on the road, and we were left listening to terrestrial radio as it faded in and out over the hills and dales.

When we pulled into the driveway, having brought home almost as much stuff as we had left with, the Passat TDI’s fuel gauge was slightly above one-quarter, and the distance to empty readout said we had more than enough fuel to drive nearly to the tip of Michigan’s mitten — Traverse City — before we had to refuel. However, after nearly nine hours behind the wheel I was tired, and had no desire to run the Passat dry. It’s endurance was greater than mine.

The Virtual Driver