Emergent Properties of my Car and their Effects on the Fluidity of Traffic Flow

My car is getting better gas mileage than it was a couple weeks ago, and it was already pretty good. Sometimes I think that it is self-organizing, like life. On the way to work today there was a lot of traffic, yet my overall gas mileage for the past two or three weeks still went up from 32.1 mpg to 32.2 mpg. I would've thought, if anything, that the traffic would have made it go down. Yet, I can't help but wonder if the traffic was a result of an emergent phenomenon in my car's engine which lowered its entropy, thereby increasing the entropy of the cars around me, resulting in traffic. Or it could be because of the construction delays caused by the work that's done on the eastbound lanes of the expressway on Friday during the Summer to piss off the people going to the Hamptons. However, I don't see why these two phenomena are necessarily independent of each other.