I just brought a 2000 seville SLS, 4.6L, " Y" engine code w/ 69k mi. (8/07). My first question is your opinion of Synthetic oils. My car has 73K mi and I put Royal Purple, 5w-30 Synthetic oil & Lucas Synthetic oil additive and installed an K& N Air filter. Was this a wise decision? My second question is, Isn't it a sign that a carbon coating in the tailpipe a sign of a engine running lean. If it is what can I do to fix this? Should I tune it up before 100K mark? I don't no what kind of care or maintance was done before I brought it. I'm planning on installinstalling Denso's Iridium spark plugs after the holidays. Any thougths? It took me a half a tank of gas ($40) to travel 180 mi (upstate PA, other side of the Pocono mountains), is this suppose to happen? YIKES!
Tuesday, November 20th, 2007 AT 12:07 PM