Phillips 100AD is a single weight (SAE 50) with ashless dispersant for piston engine planes.
Phillips 66® Type A Aviation Oil is an ashless dispersant, single-grade engine oil specially formulated for use in aircraft piston engines. The ashless dispersant formulation helps minimize the formation of engine sludge, varnish, piston deposits and combustion chamber deposits, resulting in a much cleaner engine compared with the use of straight (non-dispersant) mineral oils.