From cash back to travel bonuses, credit cards run the gamut with rewards. But a new study finds that those tied to gas stations are nothing to get pumped up about.

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CreditCards.com studied more than two dozen gasoline credit cards. The website found that the rewards, which typically come in cents-per-gallon discounts, trail what many competing credit cards offer — and they slap ongoing balances with higher interest rates to boot.

CreditCards.com analyzed 28 gasoline credit cards — both the type you can only spend at specific stations and the general-purpose cards affiliated with a gasoline brand — and found the average discount amounted to 5 cents off per gallon. That’s worthwhile if you live in certain Southern states where the average cost of regular gasoline is well under $2.50 per gallon (all fuel prices are from AAA as of April 9). At that, the rewards knock off a little more than 2 percent.

Such cards are less ideal if your car needs premium fuel or if you live on the West Coast, Hawaii or Alaska, where a gallon of regular gas runs well over $3. At that, the rewards amount to only about 1.5 percent off.

Indeed, if you compare the discount to the national average for a gallon of regular gas, $2.66, 5 cents amounts to less than 2 percent off. That trails the rewards rate from many leading cash-back or travel-rewards cards, CreditCards.com notes.

What’s more: Many cash-back credit cards offer specific bonuses on fuel purchases, regardless of brand. Credit cards tied to a specific gas brand, by contrast, typically give maximum rewards only at affiliated stations. On a given day, those stations may not have the cheapest prices in your area.

Still, many gasoline credit cards have higher rewards for an introductory period. In the first 30 days, the Drive Savvy credit card at Phillips 66, Conoco and 76 stations gives 50 cents off per gallon if you meet its minimums. In the first 90 days, two BP-affiliated credit cards give 25 cents off per gallon for every $100 spent.

“If you’re going on a big road trip this summer, then that can save you some real money,” said Matt Schulz, a senior analyst at CreditCards.com. “But, generally speaking, for folks who are just going to use these cards in their everyday life, once you get past those introductory offers, these cards don’t necessarily match up to a standard general-purpose card.”

Still, credit cards tied to gasoline brands may offer lower credit thresholds for acceptance — something that “can work as a stepping-stone card for someone who’s getting started with credit or rebuilding bad credit,” Schulz said. So-called “retail cards,” which are tied to everything from department stores to gas stations, are often the only options for consumers with low or limited credit.

But if you don’t pay off your balance each month, they’ll cost you. Interest rates for gasoline credit cards averaged 23.61 percent, CreditCards.com found. That’s almost 7 percentage points higher than the national average for all credit cards.

“It’s incredibly important, because of how high the interest rates are, that you really, really need to focus on paying down that balance as soon as you can,” Schulz warned.