With fuel prices on the rise, residents in southwestern Connecticut are tuning in to a new AAA study on improving gas mileage. The report says that turning off a car's air conditioning will not improve its efficiency, nor will having a clean air filter. Instead, AAA officials suggest drivers avoid high-octane fuel and sporadic acceleration, and get the car's engine checked regularly. The study also says that the time of day when people choose to fill their tanks is irrelevant. Lawmakers propose gas tax cap to ease pain at the pump