I overheard Tom and Ray's recent show and something about how many miles before an oil change for synthetic oil vs. conventional. I recall them saying that some 30,000 miles minimum may elapse before an oil change is necessary with synthetic oils. Did I hear this right? I went out and bought some synthetic oil for two of my five cars to give it a try, and asked the parts salesperson at Pep Boys what he thought of how many miles before a change. He said only 6000 before a change is needed ( I bought Castrol fully synthetic... they also carry a cheaper synthetic blend...) He told me to also buy the premium oil filter for this purpose, which I did (Fram "Tough Guard" series). Now I have some questions:
how often to change this synthetic?
how often to change the filter?
what about the dirt and engine debris, which I assume still will accumulate in the oil... where does it go after so many miles and isn't it good to get this stuff outta there? (conventional oil gets dirty with this stuff the filter cannot remove, so why would it be different with syn?
what grade for my climate/auto type/age (Los Angeles, 38000 mi 2004 Toyota v6 highlander and 130000 mi 1999 Ford F250 Super Duty)... I bought 10w40
do I need to gauge the oil changes based on physical inspection of the oil? (as my salesman said, as he brought me to a display device of gears in a see thru housing that showed the difference in tackiness of new and worn oils).
I would like to go 30000 or more on a change. Anyone behind me?
Oh, and what happened to the synthetic oil type I used long ago... it was black and like graphite straight out of the bottle... is this still sold? My new syn is unexpectedly like regular oil.