I usually just take the speed limit and add 10mph. I have never been stopped for anything less than this. It all depends on what mood the officer is in, or if hez sitting there just waiting for someone to come along and give a ticket to, ur probably not going to get out of it. I was doin 85 in a 55 down some back county roads on my way to the fair one year and met a Sheriff. He just stuck his hand up and pointed down, saying SLOW DOWN!
I figured me must have been on his way home to get laid or something, but then again I never get anything other than a warning from Sheriffs around here.....except for the ones in Sioux County....they suck