I gathered it was about being the most efficient (in terms of fuel usage) at any given engine speed? Moving it lower would decrease economy but perk up engine response... Maybe not?
I found a thread somewhere saying you could buy some thing (MSD?) that could be used to alter the point at which VICS engages. So people seem to get some benefit from altering it.
Besides, If mazda tuned all their engines to the best possible output from factory, then why does everyone modify them :P
