I usually follow the "5 over" rule everywhere. It's generally not enough to get you a ticket and that extra 5 mph seems to better fit the roads I travel on most. But if the rest of traffic is flowing faster or slower I'll usually pace myself with them.

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'05 X3 3.0i Alpine White/Gray Leather/Alum. Trim
Sport/Steptronic/Servotronic/Panoramic
Prem. Sound/Staggered 18" Style 114 Y-Spokes