Originally Posted by floydarogers
ST810 Advanced Diesel Technology Workbook.pdf (part of training for BMW techs):
High Pressure Fuel System
The high pressure fuel system is mostly identical in design and
function as compared to the European version. However, some
components have been adapted to the different fuel specification.
These components are:
• High-pressure pump
• Fuel rail
• Fuel injectors.
These adaptations are restricted to different coatings and materials
on the inside.
These coatings are for lubricity differences. HOWEVER, if you read the paper on VW HPFP failures for the newer Bosch HPFP they found that actual lubricity levels were better than US spec and in some cases met Euro spec. This was true for an overwhelming number of the samples. Just wanted to make that known.