Warning: the old guy at the auto parts store in Reno told me my oil changes were doing more harm than good
So I'm standing at the counter buying my usual 5 quarts and a filter, and this older fella behind the register asks how often I change it. I tell him every 3,000 miles like my dad taught me. He just shakes his head and says 'you're pouring money down the drain and starving your engine at the same time.' Turns out my car takes full synthetic and the manual says 7,500 miles. I'd been dumping good oil every 3k for almost 4 years. I switched to following the manual and grabbing a jug when it's on sale instead. Now I'm wondering how much cash I burned. Anybody else get corrected at the parts counter like that?