I've spoken with a fuels/lubes chemist about this. He says that lubricity in current D2 fuels may indeed be too low for certain older pumps, but that it varies for different fuels. Some may be fine right from the pump. Adding a few oz. of oil should help, but he recommends a straight-weight, low-ash oil. The VI improvers in multi-vis oils can be a problem. A 2-stroke oil would probably be best, as it's ash-free and made to mix & burn.