As gas prices rise and consumers look for relief at the pumps, a host of cheap gas offers flood the market. Grocery store chains and discount warehouses are jumping into the gas business with lower-than-the-competitor's prices. Meanwhile, oil companies and even credit cards, offer gas-buying incentives, to lure loyal customers. But is this where the real savings is for motorists?

In general, these offers "depend on how much you shop there and how conveniently located their stations are," said Southern California Auto Club spokesman, Elaine Beno. After all, it doesn't make sense to drive miles out of your way to save pennies on a gallon of gas.

Still, to the casual observer, a 5-cent-per-gallon reduction in gas prices seems like a lot when you are filling a 20-gallon tank. Jason Toews, co-founder of Gasbuddy.com, points out that many such gas savings programs require a membership, which can be $35 to $50 a year. "Right off the top you have to make that money back in savings. Now, if you do a lot of shopping it might be worth it. But is it convenient? If you live close it might work. If not, you might burn more gas getting there, plus your time."

Beno echoed these comments, pointing out that people are "focused on gas prices because they stand next to the pump watching the numbers flying by." In actuality, gasoline isn't the most expensive part of a road trip, she said. Instead, the lodging, meals and other expenses cost more — and offer the greatest chance for savings.

A financial expert contacted by Edmunds.com said that when weighing these come-ons "you have to look at the big financial picture. If it is a discount warehouse, is there a membership to join? If it is a rebate for signing up for a credit card, when do you get your money back? With credit cards you have to be careful of late fees and high interest rates."

Credit card companies have many promotional programs to get you hooked on using their card, a financial advisor said. "Even very disciplined people are occasionally caught not being able to pay off the full balance," a financial advisor said. "If you miss even one payment, you will have lost all the savings you got on cheaper gas."