Interesting, informative forum. I have a 2004 Camry with 2AZ-FE 4 cylinder engine. After reading information from this link, I question whether automaker specs for oil in US market is designed for optimum lubrication or for eeking out a few tenths of MPG for CAFE. www.epa.gov/otaq/cert/dearmfr/ccd0112.pdf I'm interested in what oil viscosity Toyota specifies in other parts of the world for this engine. I live in so. CA., trip length nearly always 40 miles or more, frequent extreme high temps during summer. I would prefer to use the Toyota US recommended oil viscosity for fuel economy purposes but feel this recommendation may be influenced by other factors. Any owners of 2AZ-FE 4 cylinder engine Toyotas from areas other than US; could you post the Toyota oil recommendation?