I recently upgraded from the sport 15"s to some 16"s and i was wondering if there are any changes to the electric power steering system. There probably isn't but i fig i'd ask. The new tires have much better grip so i think thats why it feels a bit more stiff plus the added size.

Anyways
cheers

 

There should be no change at all. Ever.

It probably feels stiff because the tire for the 16" rim has a smaller (and probably stiffer) sidewall than the tire made for the 15" rims.

 

the steering could feel differently if you're using low offset wheels
and wider wheels/tires, tire types. tends to tramline easier.

you can remedy that a little by a slight toe-in vs the current
setting you have.

 

yea, it can always feel different when going to a diff size, but there should be no change