Interest rates on new credit card offers rose this week, according to the CreditCards.com Weekly Credit Card Rate Report.
The national average annual percentage rate ( APR ) on new card offers hit 15 percent Wednesday, after hovering just below 15 percent for eight straight weeks.
This week marks just the sixth time this year that average rates have risen. After starting out the year near record highs, at 15.22 percent, average rates hovered between 14.9 percent and 15 percent for most of the year.
When average rates did move in recent months, the changes were minor. According to CreditCards.com data, average rates haven't dropped below 14.8 percent since July 2011, and have remained stubbornly above 14.6 percent since October 2010 .
Changes made by ExxonMobil spur this week's rise in rates
This week's change to the national average was minor as well -- rising just 0.02 percent to hit the 15 percent mark. The change was brought on by the replacement in the CreditCards.com database of a discontinued gas card, the ExxonMobil Platinum MasterCard, with a similar gas rewards card, the ExxonMobil Preferred Smart Card.
The added card features a significantly higher interest rate -- 24.99 percent -- than the card it replaced, helping push up the national average.
The ExxonMobil Preferred Smart Card is not only more expensive than the discontinued card, it's also more limited in its use. Unlike the ExxonMobil Platinum MasterCard, the ExxonMobil Preferred Smart Card is not co-branded and therefore can be used to make purchases only at ExxonMobil fuel stations and through ExxonMobil providers, such as the ExxonMobil Preferred Smart Card Travel Agency.
Co-branded cards, which can be used anywhere, tend to be less expensive than gas or store cards tied to only one retailer. However, gas cards in general are often significantly more expensive than other credit cards on the market. For example, among the gas cards that CreditCards.com tracks, the average APR is currently 22.89 percent. The average APR for rewards cards, by contrast, is 14.84 perent.
Retail chain Best Buy also makes changes to its credit card portfolio
The national average was also impacted this week by a change to the Best Buy RewardZone Platinum MasterCard. The co-branded retail card's APR was lowered from 21.74 percent to 17.99 percent this week. The change wasn't big enough to counteract the higher rate gas card, however.
The retail chain's new rate on its co-branded credit card remains relatively high compared to other rewards cards. However, new cardholders won't feel the impact of the card's standard interest rate anytime soon. Best Buy, which has suffered significant financial setbacks in recent months, also changed course on its promotional policy for the Best Buy RewardZone Platinum MasterCard.
Applicants can now take advantage of an introductory rate of 11.9 percent on purchases for a record 48 months. That means cardholders won't have to pay the card's standard APR, which is among the costliest for rewards cards, for four years.
The long-term promotion makes the Best Buy RewardZone Platinum MasterCard one of the most inexpensive retail credit cards on the market -- at least until the card turns five.
Among the retail cards that CreditCards.com tracks, only two cards feature a lower APR for cardholders with the best credit -- the Nordstrom Visa Signature card, which features a minimum APR of 10.9 percent, and the Cabela's Club Visa card, which features a minimum APR of 9.99 percent. Only one other retail card, in turn, the SonyCard Visa from Capital One , features a promotional APR on purchases. New SonyCard Visa cardholders can take advantage of 10 months of interest-free purchases before they have to start paying the card's standard APR, which ranges from 13.9 percent to 24.9 percent.
The average APR for retail cards tracked by CreditCards.com is currently 16.47 percent.See related: Despite chipless iPhone 5, smartphones march on as payment tools