"Free" Toyota Care oil changes in my 2012 are done. Synthetic or conventional oil?

[Hershey]

These are Virgin Oil Analysis of 5w-30 synthetics from Petroleum Quality Institute of America ( P.Q.I.A. ) .

1.) SHELL > http://www.pqiamerica.com/March2013P...lashellsyn.htm

2.) PENNZOIL Platinum > http://www.pqiamerica.com/March2013PCMO/pennzoilplt.htm

3.) MOBIL 1 > http://www.pqiamerica.com/March2013PCMO/mobil1.htm

4.) HAVOLINE > http://www.pqiamerica.com/March2013PCMO/havoline.htm

5.) AMSOIL O.E. > http://www.pqiamerica.com/March2013PCMO/Amsoil.htm

6.) VALVOLINE Synpower > http://www.pqiamerica.com/March2013P...lvolinesyn.htm

Here are few for 5w-30 conventional oils :

1.) PENNZOIL > http://www.pqiamerica.com/Pennzoil.htm

2.) SHELL > http://www.pqiamerica.com/ShellFormula.htm

3.) CASTROL GTX > http://www.pqiamerica.com/CastrolGTX.htm

4.) MOBIL Special > http://www.pqiamerica.com/ExxonMobilSpecial.htm

5.) TOYOTA ( Mobil ? ) > http://www.pqiamerica.com/Janaury%20...lts/toyota.htm

6.) VALVOLINE Premium > http://www.pqiamerica.com/Valvoline.htm

Go to P.Q.I.A. for many other tests of motor oil , tranny fluid , etc. , http://www.pqiamerica.com/ .