The Ultimate Diesel Guide is a booklet about the diesels on the Island of Sodor.
Characters
- Thomas
- Gordon
- Percy
- Duck
- Bill
- Emily
- Belle
- Diesel
- Daisy
- BoCo
- Mavis
- Derek
- 'Arry and Bert
- Diesel 10
- Salty
- Dennis
- Den
- Dart
- Sidney
- Norman
- Paxton
- Flynn
- Skarloey
- Rusty
- Cora
Trivia
- 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, Class 40, Splatter and Dodge were not included.
- This book reveals Dennis and Norman are twins.
Goofs
- On the front cover, Salty's bufferbeam is not weathered.