I took the old SAT earlier this year and I got a 1640, so naturally, I’m going to take it again. The problem is I already bought flashcards and 2 prep books for the old SAT. Could I still use those to study for the new SAT?
If money is the issue, use free Khanacademy.org prep and the 4 free practice tests posted there.
@Julie3 What if I told you that you can google ? 
A common opinion (which I share) on CC is that you should stick to the CB authentic materials as much as possible when preparing for the SAT.
@nw2this It’s a bit condescending making an assumption that the OP’s main concern is money - it’s safe to assume though that @Julie3 knows that the new SAT is different; the question was whether old materials are completely obsolete or there is still something useful in them.
A few helpful threads:
http://talk.collegeconfidential.com/sat-preparation/1861757-new-sat-self-studying.html
http://talk.collegeconfidential.com/sat-preparation/1861572-new-sat-math-prep.html
http://talk.collegeconfidential.com/discussion/comment/19259146#Comment_19259146
http://talk.collegeconfidential.com/discussion/comment/19182358#Comment_19182358
@Julie3 Just scan the older pages of this forum - you’ll find a good number of discussions on how to prepare for the new SAT.
Some skills overlap, but the tests are really different.
I did not assume, I said IF money was the issue. I thought money MIGHT be the issue because it sounded like OP wanted to make the best use of the money he/she had already spent and did not want to spend more unnecessarily.
I was not being condescending at all, I was suggesting a way OP could get access to current materials without making another purchase.
The tests are different. IMO, the math is a bit harder because there is no calculator on one portion that has a hard time limit. The reading is a lot different. The writing is formatted differently, but is largely the same (you can’t test grammar differently).
@nw2this My apologies - I rushed to conclusions without waiting for Julie3 to respond. It just seemed to me that it was clear that money was not the main problem, if at all.
You’ll be wasting a lot of valuable time using the old material because you’ll have to distinguish what you can and cannot use for the New SAT.
Seems like a dumb way to spend your time.
Use the 4 Official SAT tests and Khan Academy. And if you need more material, there are plenty of books geared towards the New SAT. They may not be great because they mainly recycle official material, but at least they will address content that most likely will be on the real SAT.
I sold my old SAT books and bought new books