GOOD DAY FOR: British Prius owners, after London said it will start charging a $50-a-day carbon emissions fee in October for SUVs and other gas-guzzlers that drive in the city. For the past five years, London has levied a “congestion charge,” now set at $16 dollars a day, on private cars to reduce city traffic. Fuel-efficient cars will no longer have to pay the congestion fee. (Los Angeles Times, free registration)

BAD DAY FOR: Spreading the savings, as Capital One recently changed several of its variable-rate credit cards to fixed-rate cards, meaning new cardholders won’t see any benefit from falling interest rates. Banks prefer variable rates when interest rates are rising. “If rates continue to fall, we’re going to see more banks convert to fixed rates,” said Curtis Arnold of CardRatings-dot-com. (The Wall Street Journal)