We have NO actual mechanical limited slip differential either as standard, or as an option from the factory on our Mk7/'7.5' Fiesta STs.
In England/Europe the M-Sport special edition ST had a Quaife diff included as part of the package.
The current England/Europe/rest of world ONLY Mk
8 Fiesta ST does have a limited slip standard (at the very least with an optional package
).
Some consider our traction control/torque vectoring/ESC system to be a sort of 'electronic' limited slip diff. I personally do NOT see that system in this way.