https://www.lrsoc.com/forum/forum_files/ServiceBulletinX3.pdf 5147 – FREQUENCY OF OIL CHANGE / UPPER CYLINDER LUBRICATION
https://www.lrsoc.com/forum/forum_files/ServiceBulletinX2.pdf 5106 – 1950-51 LAND-ROVER RECOMMENDED LUBRICANTS
https://www.lrsoc.com/forum/forum_files/ServiceBulletinA4.pdf 5125 – A4 ENGINE: EXCESSIVE OIL CONSUMPTION