1) Use 10w30 for high milage engines. Seems to slow consumption.
2) About 30 Miles or so before you next oil change, add sea foam to the oil. Lots of you tube videos on this.
3) Add sea foam to brake vacuum line port on the intake manifold. Lots of Youtube videos as well.
Change every fluid you can think of. Change spark plugs. Basically just give it the best tune up you can.