- "The new engines are an improvement over the P-s3s—fuel efficiency is 15 percent better and the heat exchangers are less prone to flux."
- ―Piers Roddance
The SFS P-s4 ion engine was a twin ion engine developed by Sienar Fleet Systems. It was an improvement over the old P-s3 ion engines, its fuel efficiency was 15 percent better and the heat exchangers were less prone to flux, qualifying as the primary engine system of the TIE/ln space superiority starfighter. They were also used by TIE/sa bombers, TIE/rb heavy starfighters, TIE/sh shuttles, and TIE Boarding Craft.
As P-s4 ion engines make an appearance every time a TIE/LN starfighter does, this list contains only specific mentions of P-s4 ion engines.
- Servants of the Empire: Edge of the Galaxy (First identified as P-s4 ion engine)
- TIE Fighter Owners' Workshop Manual (First pictured)