After I had my 4runner for only a month or so I just brought my 95 in for a check up. I could smell oil burning but could not find anything on the ground or on the undercarriage. After new valve cover gaskets, I asked him to change plug & plug wires because I was only getting around 13 MPG. My Mechanic thought that these were the original plug & plug wires. After 163K I would have never thought it would still run, but it was. I can't wait to see how much my mileage changes.