Yeah I really like wix/napa. A $40 oil change? $22.47 for valvoline full syn oil, $6.29 for a wix filter, tax(here .06%) = $30.49 I did mine for a few bucks cheaper when I got a purolator for like $3.50. It depends on how much gas is in it really, but any is not good. It probably breaks down the detergents in the oil too.