Recently a friend asked a police officer if he gives drivers 10MPH over the limit before ticketing. His answer was that his chief told the officers not to ticket anyone for less than 10 over. (That department, however, has a rep for writing tickets at 2-5MPH over the limit.)
I tried to explain that the speed limit is the speed Limit; i.e., the posted speed limit is the maximum speed he should drive on the roadway. "Well, but, the cop said ..."
It doesn't matter what the cop says. Will he go to court with you? I asked an Illinois State Police trooper exactly that, after he had told me over the phone to just "go with the flow" on the Tollway, even though I had just complained that the "flow" was going 72MPH in a 55MPH zone.
And even if a cop did go to court with you, it wouldn't matter. And shouldn't matter.
The speed limit is the speed Limit. If you drive faster than that, you do so at your own peril.
The minimum fine now is $120, and that's if you can mail it in or pay it without a court appearance. If the cop marks that little box "Must Appear", then he has just arranged for it to cost you another $150 or so (or more), unless you can beat it completely.