Here are four common fuel claims we want to put straight:

Claim #1: Where you fill up matters.
AMA says: TRUE. Sometimes the most convenient places to buy gas are the most expensive, especially stations along freeways and highways.

Claim #2: Over-inflate tires for better mileage.
AMA says: FALSE. While too-low tires will decrease gas mileage, some think over-inflating will do the opposite. While you may see a VERY slight increase (as in barely measureable) in fuel economy, what you’re really doing is reducing your car’s handling and making your tires wear more quickly. This won’t be offset by any fuel savings so your best bet is to keep tires inflated to the recommended pressure listed on the inside of the driver’s side door or in the owner’s manual. Also, filling tires with nitrogen will help keep your tire pressures more stable.

Claim #3: Open windows cause drag.
AMA says: FALSE. According to Consumer Reports, who tested out this theory, the air conditioner taxes fuel consumption more than the aerodynamic drag caused by open windows. Consumer Reports tested using a Honda Accord’s air conditioner while driving at 65 mph and found that it reduced the vehicle’s gas mileage by more than 1.3 km/L. The effect of opening the windows at 100 km/h (with the AC off), however, was not measurable.

Claim #4: Gas boycotts will force stations to lower their prices.
AMA says: FALSE. You’ll occasionally see plans to boycott gas stations to help reduce prices. While there have been daylong boycotts that have garnered national media attention, the resulting claims that prices dropped overnight are usually not true. Even if drivers avoid buying gas on a certain day, they’ll have to fill up in the days before or after. A station doesn’t make or break itself over a single day.