Steam Engines vs. Diesel Engines (also known as Steamies vs Diesels) is a promotional video for the special, Day of the Diesels and it tells the difference between steam engines and diesel engines. Keith Wickham narrates the video in the UK and Greg Tiernan narrates the video in the US. It was produced in 2010 by Nitrogen Studios and released in 2011; ready for Day of the Diesels.
The animation has the 3D Maya Models go into an XRay like mode or view. The sound changes significantly between the UK and US dub. The UK dub uses the sounds used between the thirteenth and the sixteenth series, while the US dub uses the sounds used between the eighth and the twelfth series.