Is the SCT ECONOMIZER fuel saving hand held programmer the same as the SCT3! I have a chance at getting a really good deal on one... can i still upload perofrmance custom tunes?

The Economizer is for better gas milage and the SCT3 is for performance, read about both:

http://www.sctflash.com/Economizer.php

http://www.sctflash.com/X3.php

I believe althoughtthey are both the 'same' hardware - the Econo is 'locked' and cannot be used as a standard X3 - uploading new tunes and custom.

They did the same thing with the XCal2 - they created a new model that SCT sold directly with pre-loaded tunes that you could not use as an 'open' XCal2. It allowed SCT to sell the units directly to the customer without competing with their VAR channel (sort of). Later, they released a firmware upgrade to convert the unit to a fully functioning XCal2 but it wiped out the pre-loaded tunes and you had to work with a VAR for custom tuning.