My dad used to change the oil in his old Chevies about once a year and he drove 30 mile round trips to work every day. In addition he did his reg shopping yearly holidays, etc.Then when the old beast would reach 160-180,000 miles he would flog it.So I change my oil regularly about every 8-10,000 miles as well.At the present I drive a 77 Nova/305/auto with 190,000 miles.I still have not had to pull my valve covers or timing chain cover.I have no lifter noise or anything.I have however never changed the transmission or differencial oil.The point is, I have apparently no sign of any wear and tear on the running gear,so how often should a person change his oils to be cost efficient?
