I did a complete tune up recently, oil, filter, cone filter, plugs, wires, trany fluid and filter, fuel filter, greased all the fittings, ran a bottle of injector cleaner, ran a bottle of power steering conditioner, both lucas, cleaned the air flow sensor, cleaned the throttle body, and a new belt, does'nt really count, I know, and last but not least, a new 02 sensor. All this resulted in one smooth running engine, getting about 15 mpg street, and about 19-20 mpg highway, not bad for 215,000 mile engine.