For Diesels I found running Howes lubricator year round Yes I know you realy only need it during the winter But, I pick up 1 MPG avg. 10% and I just replaced the factory injectors 11 years old and 336919 miles.
Also preventive maintenance comes in to play.
Valve lash check and adjust every 100K, Filters for the Allison and fuel filters every 25,000 Air filter at least once a year depending on driving conditions and fuel injector service with Diesel Purge twice a year.
Sure it will cost a few extra bucks but it pays off in uptime and mileage.
Be safe
Bob Wolf