Best fuel additive to prolong IP life?

[volvo 4 life]

I know on many other mechanical diesels, it is a good idea to run a fuel lubricator since the ULSD fuel sold today lacks the lubricity of the high sulfur diesel. What is the best additive for the VE pump on the D24? I've read power service grey bottle is good for most trucks, and I've also heard 2 stroke oil works well. I just want to ensure the pump is getting the lubrication it needs to live a long life.