According to SmartMoney.com, these are the 5 things gas stations won’t tell you – but you should definitely know about.

1. “Good luck finding the best deal”: Most gas stations are branded, which means a major oil company has their sign hanging out front. That’s bad because gas station owners don’t have a choice when it comes to buying fuel. They can’t shop around for the best deal. The result is that within a mile you could very easily see up to a 46 cent difference in the price of a gallon of gas. 

2. “I hate it when gas prices go up”: Gas stations earn on average between 10 and 15 cents on a gallon of gas. Ironically, they earn the least when prices are highest. And here’s another thing they don’t want you to know. Gas stations would much rather you pay with a debit card instead of a credit card because they get hit with higher fees if you use a credit card. The trick they try to pull is when you swipe your card a message will pop up on the screen asking “Is this a debit card?” If you press “yes,” the gas station makes more money. If you press no, which you can do, they earn less per gallon.

3. “My gas isn’t better for your car: it’s just more expensive”: Oil companies spend a lot of money advertising why their gas is better than the other folks across the street. But today more than ever, one gallon of gas is as good as the next. While it’s true that additives help to clean your engine, what the companies fail to tell you is that ALL gas has additives. It’s been the law since 1994.

4. “If you’re smart, you’ll put that debit card away”: That’s a bunch of hooey! Your debit card might be a convenient way to pay for gas, but it’s a no-win proposition. When you swipe a debit card at the pump, the bank doesn’t know how much money you’ll be spending until you’ve finished pumping. So when you swipe that card, some banks set aside some of your money, up to $100, until the station sends over its bulk transactions, which can take up to three days. 

5. “It’s a gallon when I say it’s a gallon”: It’s hard to know if you’re getting all the gas you paid for at the pump. But in some places there’s a good chance you’re not. Each state has a department to checks pumps for accuracy, but in some areas it can be years between inspections. Take Arizona as an example. Arizona only has 18 people to check the state’s 2,300 stations. That means it can be up to four years in between inspections. In 2005, 30% of the more than 2,000 complaints the state received were valid, and stations paid nearly $200,000 in fines.