Quote Originally Posted by green91
you guys do realize the reason you change your oil isn't because the oil breaks down after 3-5k right? yes synthetics last longer. but the reason for oil changes is because of the carbon contamination due to the combustion process getting into the oil. hence why oil gets darker. synthetics and fossil oils alike suffer this same fate.. so those of you who run synthetics to extend your oil change intervals may actually be doing more harm than good.
Great point to mention that. If any of ya'll do decide to go longer between oil changes, make sure that royal purple isn't in your crank case. I personally think that it's highly overpriced. I found out that Shell Rotella has zinc in it and I was convinced that (well after my buddy ran it in his turbo car without any problems) it would do well in my vehicles. Shell Rotella 15w40 FTW