Watching gas prices slowly inch back up in recent weeks is cause for concern among many motorists, especially those who may be trying to plan an affordable road trip this summer. Maybe that's what's sparked the latest round of e-mail forwards that warn about evil gas station operators scheming to cheat us at the gas pump. The Doc has received several versions of this e-mail.
Most variations start out with the ominous assertion "This is a true story, so read it carefully" followed by an account of a small-town everyman or woman who discovered that he/she was ripped off by a gas pump rigged to make it seem like it delivered more fuel than it actually did.
The typical scenario recounts the tale of someone pulling up to the gas pump with a quarter of a tank already in their vehicle that holds 14 gallons of fuel and watching in horror as the pump indicates that they have pumped 18 or more gallons.
A little research tells us that the story — although it has some elements of fact — is mostly an urban legend perpetuated by well-meaning folks who can't resist clicking the forward button.
Although a few Cisco service stations in Georgia were closed a few years ago because of rigged pumps that shorted customers about a quart for every 5 gallons purchased, experts say there isn't an epidemic of thievery on the part of gas station owners.
Snopes.com has several iterations of the gas pump rip-off e-mail posted on its site, and says that while gas pumps may indeed be rigged to rip off customers, worn equipment is usually the culprit in most cases of gas shorting, which can cause malfunctions such as clogged pumps and calibration problems.
Some pumps, for example, may advance past zero before any gas has been pumped into your car. This is a calibration problem that arises when pump valves wear out. In some cases, customers may actually receive more gas than they pay for.
State inspectors regularly check gas pumps for accuracy but consumers keen on testing the veracity of the pumps at their local gas station themselves recommend the 10 gallon test: pump exactly 10 gallons of gas into your tank, then look at the dollar amount displayed. If the dollar amount is not exactly 10 times the price of the fuel, then the pumps are not working properly, they say. But this isn't a foolproof method as several factors may come in to play.
Even when the pump displays the correct total in dollars per volume pumped, the volume still could have been measured inaccurately.
Cool tip: Another factor that can affect your gas gauge is temperature. Gas expands slightly when temperatures are higher, so some experts recommend gassing up in the morning when cooler overnight temperatures will mean slightly cooler gasoline, which is denser than the super-heated gas you pump midafternoon. Cooler fuel could mean a tad more gas in your tank and better mileage.
Cash vs. credit: Prices at the pump can vary from the price displayed on roadside signs. Pay attention to price differences based on method of payment. You can pay more or less per gallon than the price displayed on the roadside price sign depending on whether you use cash, debit or credit cards.
Saving money on fuel is often a matter of common sense and planning.
Fuel additives: The Federal Trade Commission recommends that motorists be skeptical of gas tank add-ins that claim to improve gas mileage, as they don't deliver better mileage and can increase emissions and even damage the engine. Rely on your vehicle's manual to prescribe the best octane level for your car, which in most cases is regular octane. The FTC says that using higher octane gas than what's recommended by the manufacturer doesn't make your car run better — it only costs you more money.
Lead foot: Other simple gas-saving measures include driving within posted speed limits (exceeding 60 mph burns more gas), avoiding aggressive driving, including sudden starts that require "punching" the gas pedal, removing excess weight from the trunk of your car, and avoiding carrying items on a roof rack, which creates wind resistance and can decrease fuel economy by 5 percent.
Plan ahead: Several price monitoring Web sites display the name and address of area gas stations sorted by ZIP code, with the date and time of the most recent price update. The cheapest gas in your neighborhood can be found with a few mouse clicks before you hit the road. The Doc likes www.gasbuddy.com .
Until next week, happy and safe motoring!
Please e-mail Dr. Delay at firstname.lastname@example.org to share your traffic concerns, comments and questions.