[TheMAN]

smoke only at startup is usually bad valve seals out, worn cylinder bores, or bad piston rings... you can try a high mileage oil that has seal conditioners that may make the rubber pliable again and "fix" the problem, but you can't fix any wear and tear.... the smoking stops once the engine warms up because everything expands with heat and "seals" in place

smoke at high RPM is usually from crankcase blowby.... in other words, issues with the piston rings or PCV system

as with all things, try the cheapest fixes first and work your way up... if it's just the matter of a dodgy PCV valve or clogged air filter that's causing excess crankcase pressure causing VISIBLE oil consumption (smoke), then the fixes are easy and obvious