Official Guide Practice Tests- Inconsistent?-Urgent

<p>Guys I've been giving practice tests from the official guide for the past few weeks. But my friends who've already given the SAT claim that their performance on the Official Guide Practice tests to their performance on the real thing was no where near the same.
Like they scored 200-300 points less than they usually did on the tests.
Is this because the tests are inconsistent(Official?)?
Please Help me out.</p>

<p>If not the Official Guide, which books would you recommend to gauge performance on the actual test.</p>

<p>Thanks a lot
Xunxun</p>

<p>I think official books are more consistent than the 3rd party practice books. In my opinion, questions at Princeton Review’s SAT book has nothing to do with the real thing.</p>

<p>^Thanks
Anyone else?
Bump.</p>

<p>The blue book is very similar to the actual SAT. Three of the tests are actually previously administered tests, so they really should be very consistent.</p>