This sounds like a case of
premature optimization. You are almost always better off developing good readable (and therefore maintainable) code without concerning yourself too much about which of several different methodologies is theoretically better. Later, once your code is working to your satisfaction,
if you find there is a performance issue,
you should use a profiler to determine where the performance issue lies, and fix the specific problem identified by the profiler.
One of the big issues with this particular question is that it is difficult to provide any definitive answer, and even if one were provided, the
Java bytecode compiler, or the JIT compiler could have enough differences on various computers that the result could not be guaranteed. And even if it were limited to just a single architecture and operating system, there is still the risk that any future upgrades to Java on that machine could render any statement meaningless.
To get around some of these sorts of issues in general (not just in Java), you can take a step back from most algorithms and consider how complex your code is, and one way of describing that is by using
Big O notatation. However at a simplistic level, the complexity for both the enhanced for loop and the standard for loop are the same: O(n).