Hello I will help you with your question,
The Mobil is probably the best synthetic on the market. The reason the Royal Purple is not SN certified is the level of zinc phosphate it contains. The zinc does a great job of protecting metal to metal shearing wear but over time it coats the catalyst in the converter and keeps it from working so it is a trade off.
All you really need to look for is that it meets the GF-5 rating (information is on the label). This is a better test than the general SAE rating and assures that the oil will provide the best protection possible for your engine while delivering the best mileage possible.
There is no difference in oils when used in the vvti system it is just a method of delivering force.
Please let me know how I can help you
Hello again. Thanks for requesting me a second time. I see than one of my colleagues picked up the question before I received your request notification. Here in our shop, we sell Mobil One at the parts counter, along with the genuine Toyota fully synthetic oil. Regarding the VVTI system, the correct weight of oil is critical. Synthetic oil is required for the 2012 TC product. Your best bet here is the Toyota oil; it is specially formulated for your car. The VVTI system needs a specific weight of oil to operate the camshaft advance system thru the oil control valves. The VVTI system delivers oil pressure AND volume to achieve the variable timing. Using a heavier weight oil will compromise the VVT system response, and could cause the ECU to see a VVT code. If you have any questions, please feel free to respond. Thanks for choosing Just Answer.
Yes I use the correct weight ( O-20) and as I mentioned the newer Royal Purple has the GF-5 rating.
Our local Toyota dealer uses Mobil 5000 conventional for those engines not requiring synthetic and Mobil synthetic for others.
It seems Toyota has switched in the last few years to the 0-20 either because of mileage (friction) or because of the very tight tolerences the engine is built to?