My GCV160 lawnmower has been great for many, many years. It does not smoke or use any oil all season. Great little engine.
That engine has an aluminum cylinder. For longest life, change the oil after the first few hours of use to get the break-in wear metals (glitter) out. I changed my oil after every couple mows until the glitter was all gone. It took 3 or so oil changes. Now, I mow all season (about 30 hrs/season) and the oil is still clean when I change it in the fall.
I used the "Arnold's" oil that came with it for the initial fill, then the quart of Honda power equipment 10W-30 that I bought when I got the mower. When that quart of Honda oil was used up, I switched to regular Mobil 1 10W-30.
I saved the 13oz "Arnold's" oil bottle that came with the mower. I use it to measure the new oil when I do an oil change. Fill it up, dump it in.