U.S. consumers haven’t stopped spending since the Iran war drove up fuel prices. But company executives and retail analysts say many shoppers are reassessing what they buy and where. The behavior changes observed so far are subtle. They include drivers flocking to the fuel pumps at warehouse stores like Costco and Sam’s Club, but not filling up their tanks all the way. Market research firms say foot traffic is down at clothing and electronics stores. Executives from Walmart, McDonald’s and Dollar General have reported noticeable cutbacks by lower-income customers. Some economists and analysts expect a wider retrenchment as the cumulative impact of costlier gas, food and other products catches up with more people.