"Let's pay him out!"
— Cargo cars, Diesel Knows It All
- Season 1: Wilbert and Tigermoth (cameo)Frank and the Trucks (cameo)
- Season 2: Scarloey and Rheneus depart for Crewe (does not speak)
- Season 3: Cranky's Delivery Diesel's Dilemma
- Season 5: Fergus' Market Day
- Season 6: Diesel Knows It All
- Season 7: Rails on Fire
- Season 8: The New Controller (cameo)
- Season 9: The Arlesdale Rumor Railway Stowaway
- Season 10: A Normal Day for Dennis
- Season 11: Stepney and the Bluebell Branchline
- Season 12: Greetings, Montague! (does not speak), Henry's Handcar Havoc
- Season 13: Sam I Am
- Season 14: Hatt Trick (cameo)
- Season 15: The Maron Station Makeover (does not speak),Nightmare on Sodor (fantasy),Ice Ice Daisy (cameo),Polar Express Coming Through! (cameo), A Christmas Caroline
- Mentioned in The Season 13 Update, Keekre24 stated that he will not be using the 2013 CGI Diesel Model by Mattel because it is slightly rounded and it has a happy face, which does not suit Diesel's personality very well. Instead, he used the 2012 CGI Diesel Model by TOMY because it isn't as rounded as the 2013 model and it has a face that suits Diesel's personality best.
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