Post by
ImStricken06 »
https://forums.nicoclub.com/imstricken06-u194849.html
Mon Sep 10, 2012 8:35 am
Its well known with things like bearings, that when bearings "break in" they have a slight variance in the clearance they operate under, and will spin free-er and easier, and hold its spin longer. and since bearings are everywhere in the car (every pulley, every wheel, every axle, every spinning component, input & output shafts, transaxle, differential, etc.) the car might idle better, require less energy to roll/run, etc. but we are talking about miniscule. not enough to feel, but maybe enough to show up on MPG differences.