The answer is . . . no (and the reason is because you haven't provided enough information data for one to determine the precision of the distance).
"6.7 mi" you might want to argue is more precise simply because it measures this distance to the tenth of a mile
"6 mi" happens to equal "6.0 mi" which is also measured to the tenth of a mile.
Precision of a value is determined on the basis of repeatability and/or reproducibility. If the distance is measure 3 times with results that closely match each other - that's precision.
Unfortunately, you didn't provide us with enough information, so there's no way anyone could determine whether or not this measurement is precise.
