How similar are the CollegeBoard practice tests to the Official SATs?

I’ve been self-studying from old SATs and books and I realize there are a lot of differences with the new SAT. Are the practice tests that CollegeBoard provides on its website similar in format to that of the actual SAT? Is the scantron any different, is there any time difference? How is the material in each section different from that of the old SAT (i.e. no more fill-in-the-blank questions in the reading section, providing evidence for previous questions, harder math)? I’ll be transitioning to New practice tests soon and don’t want to be hit by any surprises on test day. Any input from those who’ve taken old SAT, new SAT, or both would be very appreciated.

I thought college board put the real past SAT tests as practice tests. hence some of the practice tests were real SAT tests.

Is there any way to know which practice test was which SAT? Was there no prep for any students taking March - August 2016 tests?

@cloverSTEM I am sorry, I did not get to this earlier. I do not know specifically which practice tests corresponds to which real SAT as my DD only took SAT once and decided to focus on ACT, but there were earlier posts where people pointed out the specific practice test.
If my memory serves me right, I think at least practice test #5 came from the real test. I ordered my DD’s test and only to find out that college board released it as a practice test around the same time.

If memory serves, Practice Tests 1-4 (or at least some of them) were available prior to the March 2016 test. I believe that all of Practice Tests 5-8 were actual tests that were given after March 2016, but I don’t remember which one was which. Since tests 1-4 weren’t actually administered, some people suggest that tests 5-8 are better for authentic examples/practice. Practice Tests 1-8 are all available on the CB website. They are also available in the Official College Board SAT Study Guide, 2018 Edition. The New SAT is so different from the old SAT that I definitely would not try to prep for the new SAT using old SAT materials.

My understanding is the same as @SoccerMomGenie .

IIRC, Practice Test #7 was a March 2016 SAT (I remember a Silas Marner passage)

You really want to avoid practicing old SAT tests for the new format. I’d actually recommend Khan Academy’s self study program. They ramp up the questions in difficulty and have special questions made exclusively for them working with CollegeBoard. I found their practice questions to be extremely accurate to both the PSAT and the SAT and you get to study with all of the published Practice Tests in a timed manner.

@Komeko The “tests” mentioned in this post were the actual tests in the new format.