I just bought a 2013 Toyota Tacoma with the 4 liter V6 engine. Apparently, it is one of the last Toyota engines NOT to come with synthetic oil from the factory. As a long time synthetic oil believer, can anyone tell me if there is a good reason NOT to use synthetic oil with this particular engine? The service manager thought the reason is Toyota only has 0w-20 synthetic oil, where the V6 engines require 5w-30 oil, thus they just use regular oil. I want to hear from experts on this matter, I have a jug of 5w-30 Mobil 1 ready to use. Thanks in advance.