green 2is

I know im too late in this convo, my 07 is 350 just bought burned 3 quarts in 400 miles and still no engine light, changed the pcv, white smoke is there, but anyone know if something could help? Car runs and looks great, just want to keep it running as long as possible. Has 220k miles on it, but rips through all those gears and keeps up with the 2023 bimmers. Should i use thicker oil, or start putting lucas oil stabilizer?