I was just rethinking this and usually I go with the (faster) flow pack until one or a few of the flow group starts to block in others in the group or hang on the side (and in the blind spot) of a semi or cars that should be passed and then get into the right lane and out of the way. I try not to impede the flow or speed of others that want to go like H#ll and especially never block or take away the run of a semi even to the point of slowing down and flashing the lights to let them out to do their passing. I don't care if I have to slow down to their speed as they slowly make it past the slow moving right lane vehicle, I'll make it up once they pull back in the right lane. People that block the left lane no matter how slow or fast they might be going p1$$es me off more than anything, Go as fast or slow as you want or feel comfortable but d@mnit don't impede the flow of traffic and stay the heck out of the left lane(s) once you have passed! You do that on the Autobahn and watch what happens. There are even State laws against staying in the left lane(s) too long.