I have two questions regarding engine fluids. First, I have two gallons of Toyota red coolant that are about 5 years old, but still are in the foil sealed containers. Do you think they are still OK to use? Second, my daughter just bought a 2011 Nissan Juke with a turbocharged engine. The owners manual calls for conventional oil, but I have been told that a turbo motor should use synthetic oil. Any comments about this would be appreciated. Also, if synthetic oil is used, any opinions as to the best brand (Mobil 1, Castrol Syntec, etc.)? Thanks for taking the time to address my questions. My best to all.