Some cars leave a paper trail; the Hispano-Suiza HS21-GTS left a name and a place in Hispano-Suiza's list. What follows is what can be said with a source behind it.
In context
Nearby in the Hispano-Suiza catalogue sit the HIspano-Suiza K8 and the Hispano-Suiza Alfonso XIII.
The record
The open record for the Hispano-Suiza HS21-GTS carries no verified engine, output, weight or price yet. MotorJury does not fill gaps with guesses; this entry gives the model a home in the catalogue and grows as sourced specifications and photographs arrive. Corrections: corrections@motorjury.com.