how has the act changed from before 2016?

hey guys, i’ve always thought i would take the sat, but my counselor recommended i try out both before making a final decision. i have almost zero knowledge about the act except that it has changed a little starting with 2016-2017. i have a couple questions. how exactly has it changed? are the act practice tests in the new 2016-2017 red book new tests or recycled ones? is it ok to use past act practice tests to practice for the new act? how do the practice tests in the new book compare to the actual test? thanks in advance.

ACT Red Book - 3 tests. 2 are amalgams of April & June 2015 tests mixed with old questions… 3rd is much older test. Actual test format hasn’t changed at all in terms of timing and number of questions. In reading there is now a dual passage in place of a single passage, and science now has 6 passages instead of 7. ACT Essay changed a year ago to a 40-min format, and that has since been tweaked. Definitely take the ACT at least once. It is best to use old tests to practice.

@midtntutor thank you!

Glad to help.