If I am recommending 20w-50 in this particular case, then I am taking responsibility that there will not be oil consumption issues or smoke from the exhaust, and it will work for some time (like months, years, etc.), unless / until rings, pistons, valve, seals, etc. are 100% done and rebuild / overhaul is the only solution (as I do not know of any other oil grade for Gasoline cars, which is thicker than 20w-50, and is easily available in markets from reputed brands).
However, the members suggesting 5w-30 to him; there have been instances when members switched from thick to thin oils grades on recommendations of "us", the "oil experts", when their engines were working fine on 20w-50; oil consumption issues and smoke from the exhaust started, and owners were greatly sad (No doubt, it is recommended as per manual, but some things which are practical here, do also work fine).
