I came across a 5qt jug of Wal-Mart synthetic blend 5w30 SJ rated oil. Being the cheap SOB that I am, I am wondering if I could use this oil in my 2006 Civic and change it out at say a 5000 mile OCI rather than the 8000 miles I am accustomed to. Or should I just save it for the lawnmower? Please don't flame me too harshly! Other things I found; two quarts of the original Slick 50 treatment, must be 20 years old! A quart of Rislone oil treatment (yellow bottle) a quart of STP engine treatment (Slick 50 clone) and 2 metal cans of the original STP stuff (thick as honey). I also found an old quart of gas stabilizer-does that stuff go bad too? (probably does-I just hate throwing things away!)