Michelin Premier A/S-not so good milage?

I have a 2006 Prius. I was running Michelin Hydroedge 185/65/15 with about 65,000 miles on them. My last tank I was getting 57 on computer, 54 by division after refill. My speedometer read about 3mpg over actual.

I replaced with Premier A/S 195/65/15 and after driving a few hundred miles filled up and in my normal commute (48 miles daily with 42 of them freeway at 65mph) I was getting 51.7 on the computer and 48.7 by division. I'm dissappointed with the milage but the car is quieter and I believe the feel is improved with the wider tread. I keep mys pressure at 42F, 40R. The speedometer only reads 1 mph high with these tires.

The Hydroedge gave me about 2 mpg lower than the stock tires and I was expecting improvement.

I've never asked to have tires changed, but am considering this before the 30 Michelin Promise trial period ends. This car is in NC where we get little or now snow. I might see if there are any Energy Savers available despite them being discontinued.