Slight Stiffness w/new tires & wheels

I just recently replaced my stock wheels/tires with BFG Rugged Terrain (265/65R17) and FLEXX OFFROAD-FX72 Black w/Machined Face (17" x 8").
Been driving on them for a few days now and have noticed that I can feel a slight stiffness when turning. Plus, when I let off the gas I can feel the weight difference and slow down faster than I used to with stock tires/wheels. I'm thinking its the tire pressure but wanted to see if anyone else has experienced this before.
Currently running 31 PSI and tires' max is 44 PSI.

 

P rated ?

 

Yes

 

Or would it be a problem with the backspacing or offset?

 

or that fact the the tires are heavier, I noticed the same thing with similiar tires.

 

Rolling resistance is more with an at tire. Perfectly normal observations.