re: Fastest mower for 6-7 acres

My dad has a Bad Boy Outlaw XP 61" deck 36 hp. that boy is nice a couple problems at the beginning with the wiring harness but once it was fixed she runs like a pearl. I Used it for a lawn service and it cut very well. burns gas very fast when its wide open. I could cut around 4.5-5 acres with a reasonable rpm around 3000-3100 and could do it in about 3.5-4 hrs depending on how wet the field was, with 1/4 tank left of gas.