Answer by
senthil34 (169)
Go with Royal purple in the trans. For the engine,each one has it's merits. but I'd give a slight edge to the synthetic. 10w-30. If you really want to do something to help your car,go with a complete Z-Max treatment. always run synthetic oils (transmission,rearend and engine). If you're not burning oil then stay with the same weigh that you currently are using.