Fueling Up for Free

This Thanksgiving travelers will have to account for more than just the usual traffic delays. In addition to budgeting extra time, they'll have to budget for higher gas prices, too. Although the cost of a barrel of oil has slipped from a recent high of $98 to about $91, prices have risen over the past couple of months. That hike has trickled down to local gas stations nationwide. According to the motorist club AAA, the average price for a gallon of regular unleaded was at or above $3 in 39 states and in Washington, D.C. The Energy Department also warned on Wednesday that prices could jump another 10 cents in the next few weeks.

Eager for affordable answers, some drivers are turning to gas rebate credit cards. Much like cards that rack up frequent-flier miles with every purchase, gas cards earn credits toward free fill-ups. But are they worth it? If you pay with a card that gives a 5 percent rebate, you, in effect, pay $2.85 for a gallon of gas that costs everyone else $3. Over time those cents add up. To sweeten the pot, a few cards also allow you to use rebate points at participating restaurants, airlines and stores.

But chargers beware. "If used in a savvy manner [gas rebate cards] can be beneficial," says Curtis Arnold, founder and CEO of CardRatings.com. "But part of that equation is paying off your balance every month." Break that cardinal rule and users could be saddled with interest rates of nearly 25 percent.

Not all gas rebate cards are the same. Be sure to read the fine print, says Arnold. Some gas cards issue a cap on their rebates, while other cards' rewards expire after just six months. And while some companies automatically credit cardholders' accounts, others either issue a check or actually require users to request their rebates in writing.

Which cards are worth considering? "You want a gas reward card that subscribes to the 'Keep it simple, stupid' line of thought," says Arnold. "You want a card that will require no work from you." The top five picks from CardRatings.com:

1) If you've got excellent credit, the Capital One No Hassle Points Rewards card offers a generous 2 points per dollar spent at gas stations, and major grocery and drug stores. Rewards don't expire, and there's no limit to the number of points users can earn. Also, the card offers a zero-percent APR until July 2008. After that, it's 13.4 percent.

2) The Discover Open Road Card doesn't charge an annual fee, and it offers a 5 percent cash back bonus applicable toward gas and auto repairs. It's not just for gas, either. It also includes a zero-percent introductory annual percentage rate for six months. After that, expect an APR of 10.99 to 18.99 percent, depending on your credit rating.

3) The Chase Perfectcard features a 6 percent rebate on all gas purchases for the first 90 days. After that, rewards dwindle to 3 percent. Another caveat: make sure you've got a solid credit rating and are willing to pay off your balance every month. While Chase does offer a zero-percent APR, this card's variable rate starts at 13.74 and goes up to 22.74 percent.

4) New Shell Platinum Card holders receive a 5 percent rebate on all Shell gas purchases in the first 60 days of being issued a card. During that period users also get a 5 percent rebate on the first $2,000 they spend anywhere else. After the introductory period cardholders still earn 5 percent rebates on all Shell purchases and 1 percent rebate anywhere else.

5) The Chase British Petroleum card offers new holders a 10 percent introductory rebate on BP purchases up to the first 60 days. After that initial period it offers a 5 percent rebate. After a six-month zero-percent APR, interest rates are between 14.74 and 23.75 percent, depending on your credit rating.