I know this is not Cobra related, but it would apply to any engine. Would there be any downside to switching to
synthetic oil on a 100,000 mile engine that has lived it's whole life on regular
oil? Car is a 2001 Chrysler 300-M with the 3.5L. Will the
synthetic oil "clean-up" the inside of the motor IF it is sludgy? (I'd bet the inside of this engine is very clean though as the car was meticulously maintained). I just like running
synthetic in all my vehicles compared to regular motor oil.