Driver's Seat: Running gas tank nearly dry is false economizing

Now that gas prices are crossing the $4-per-gallon mark from the Delaware River to Downingtown, filling up can be pretty depressing.

But putting off your car's fill-up can have even bigger consequences - beyond making a fuel of yourself with the tow-truck guys.

As the price has climbed, more drivers seem willing to hold out for the next fill-up. AAA MidAtlantic says calls from members who have run out of gas are up 20 percent over April 2010.

In addition, PennDot's Expressway Safety Service Patrol Trucks have been helping more motorists who are out of fuel on the Schuylkill, I-95, 202, and 422.

"Encounters with vehicles that have run out of gas are up 10 to 15 percent" since February, said Eugene Blaum, PennDot spokesman.

Rick Remington, who handles public and government affairs for AAA MidAtlantic, said the out-of-gas calls still make up only about 2 percent of the association's calls.

But AAA officials caution people that running their tanks low regularly could prove costly. Remington cites damage to the fuel pump and the intake manifold as two of the biggest worries for drivers who let the fuel dip below a quarter tank regularly.

"Trying to save a few pennies on gas there can cost hundreds of dollars in engine repairs down the road," Remington said.

Howard Pitkow, assistant director of the mechanical operations committee of Automotive Service Association, an organization of auto-shop owners and managers based in Bedford, Texas, confirms that people who drive "in the red" risk damage to their car's fuel system.

As the owner of Wagenwerx Volkswagen and Audi service in Wyndmoor, Pitkow said he doesn't see cars coming into his shop with these kinds of problems, but he does know what will happen.

"The fuel pump pulls up sediments which might be in the bottom of the tank," Pitkow said. This can ruin the fuel pump and clog the components of the fuel system.

One incentive to keep the tank full: It's not like gas is getting any cheaper, folks.

A high-tech component? I wonder if some of the increase in calls to AAA could be from people paying attention to the nifty "Distance to Empty" displays on the latest cars.

I found out how untrustworthy those readings could be while testing a Dodge Durango recently. The fleet operators don't require a full tank when I return a vehicle, and at these prices, I simply say, "Bless you, fleet operators!" and give back the minimum.

So I put enough fuel into the Durango to get me to work and back one day, expecting the fuel level to land right where it should when I was done. But as I traveled along 202 one evening, I watched the "Distance to Empty" display drop by about 10 miles (almost 5 percent) as it recalculated along one mile, and my heart sank. Fortunately, I didn't have to make the embarrassing call for help, just put a little more gas in the tank.

Staying fueled: Heck, I don't even trust gas gauges, so I don't know why I would put my faith in the new electronic version. (Probably the "Oooh, shiny!" factor.)

My first car trained me well. The 1980 Ford Fiesta had such a tiny gas gauge, and a tiny gas tank and tiny everything else, that it was impossible to read. I used to keep track of my odometer at each fill-up and make sure to buy gas every 200 or 250 miles.

Now, trip odometers help as I grow old and the memory begins to . . . uh, what were we talking about?

Hyper-miling saves - but proceed with caution: Some savvy folks claim they can squeeze extra miles out of each gallon by driving conservatively, timing stoplights, and other tricks.

AAA's Remington said those ideas are fine, but the association doesn't support the "other tricks" part, which include coasting in neutral or with the engine off, following closely behind larger vehicles ("drafting") to take advantage of lower wind resistance, or rolling through stop signs.

Keep things in check: Pitkow's advice: Keep your engine tuned, and if the "check engine" light comes on, have the car serviced.

Other standard advice: Keep your tires properly inflated and follow the other routine maintenance in your owner's manual.

And if you have AAA and you are calling for gas, don't do what one member did: He called for an emergency refuel, drove the distance that much gasoline got him, then called again for more. Or you might find yourself in the newspaper.