Originally Posted By: john_pifer
Couple questions: Has Toyota changed the clearances on the 1GR-FE, making them tighter, to run a 20W? Or, are they calling for a 20W just for economy?
Also, I know the newer versions of this engine have VVT-i on the exhaust cams as well. That brings up another question - could using a different viscosity than what is specified cause any issues with that dual VVT-i setup?
My understanding is that the only difference is the vvt on the exhaust. Pre-2010, this engine was spec'd 5w30, and after much reading of FJ forums there are a lot of guys post 2010 using 30 weights with no issues. Plus as mentioned, thicker oil is actually recommended in the manual. I've been unable to find any reference to clearances or oil drain hole sizes changing....so IMO it is for CAFE.