What size are you looking for? I cut 1.3 acres with an old 11hp 38" cut, light weight Craftsman. I have had bigger and smaller in the past, since 1986. If I use any deck over 39" it scalps too much in the drainage ditch and small hill in the front yard. A smaller deck takes longer. Also the older 8hp on a 36" size did not have enough power and you had to do double cuts. One pass on hi and then another on low. Or you have to do narrower cuts. I have found, for my yard and grass, that a 38 or 39" is right with 11 hp as the smallest size for that size deck. A larger engine will use more fuel. Also use the lightest mower to get better fuel economy.