The Ultimate Diesel Guide is a booklet about the Diesels on the Island of Sodor.
- Diesel 10
- 'Arry and Bert
- The book was given away at Day Out with Thomas events and with DVDs in the UK and US. It was also available online.
- For unknown reasons, The Diesel, Splatter, and Dodge were not included.
- On the front cover, Salty's bufferbeam isn't weathered.