Sorry but this is narishkeit. The left lane is for PASSING ONLY so it makes no diff what your speedometer reads. If you aren’t PASSING, you are not allowed to hand out in the left lane. It is DANGEROUS and you WILL get pulled over.
If you get into the left lane to pass someone, make sure you move back to the right as soon as it is safe.
From AAA:
Generally, the right lane of a freeway is for entering and exiting the traffic flow. It is a staging lane, for use at the beginning and end of your freeway run. The middle lanes are for through traffic, and the left lane is for passing. If you are not passing someone, you should not be driving in the left lane.
I drive well over 25k miles a year. It is the hangers out in the left lane who are the root of accidents!