The wider the track width the more stable and settled the car is, where as when its narrow its alot more nimble and is supposed to generate more grip hence the thinner hexes on the EC (or so it was mentioned on here before the car came out). I done some checking myself between the Mi2 and EC and i had the EC track widths coming out almost identical front and rear. It was my old Mi2 that was wider at the front than the back, only by about 1mm, something that could easily be corrected with spacers. My measurements also has the EC track widths wider than the Mi2 by about 1mm front and back.