Church-Turing thesis states that any effectively computable process is computable by a TM. Let's assume for now that it means that every physical machine is computable by a TM. Let's call it A.
Now if this process has an unbounded number of states (for example we could think of an engine in a car and take the geographic coordinates of the car as its states) we could say that A is also Turing complete.
And therefore Turing equivalent.
Edit: Let's try to see more precisely how A could be considered as Turing complete even if the physical is continuous. Let's for example consider a car moved by an engine. And let's consider a planet where towns' names are built with the classic alphabet A, B, C etc. following rules that make the number of towns on that planet potentially infinite or unbounded. Now let's imagine that my vehicle is programmed by an algorithm to drive from town to town indefinitely. Let's call these towns the states of my system. Now I am certain (but please correct me if I am wrong) that my physical system is indeed Turing complete - and not just a push down automaton. Now if you accept that any state an observer (typically a physicist) will use to describe a physical system can be coded in a finite alphabet i.e. an integer (even if the physical world is continuous) then surely we could use the vehicle experience to say that in human eyes the physical world is Turing complete.
Is that correct?