So I did my first tire rotation on the Prius v Five this past weekend and was struck by something I noticed on the backside of the 9 radial spokes - there are reliefs in the casting, which are not surprising. What is surprising is that they are not symmetrical. Does anyone know why this is? One thought I had was aerodynamic related - perhaps to kill some kind odd beat pattern or something. Another thought is that it it is opposite the Schrader valve, so maybe there is some benefit of having the dual recesses opposite that, aero or weight balancing. Last idea was that it was actually a manufacturing aide - casting is one of those fields that mixes black art with high tech, so that is always possible. Anyway, I just found this odd, and wanted to share it in hopes that someone might know something. Or we could all just play the guessing game create some new Prius mythology...
I'll guess its a combination of things. But balancing would be at the top of the list. Alloy casting is part science and part alchemy, but saving a few ounces of alloy in each casting is no small savings. A couple of those wholes look to be machined and probably relate to balancing at the factory.
Probably balancing. Makes sense that the heavier spokes, the two opposite the valve, are the heaviest (less material removed), because the valve also has the TPMS sensor on it.
