WhatClassAmIAutocross Classing Guide

SCCA® Solo classing — unofficial guide

What autocross class is a Ford Mustang GT (S550)?

FSStreetBSTStreet Touring

A stock 2015–2023 Ford Mustang GT (S550) runs in FS (Street) under the 2026 SCCA Solo Rules. Built to Street Touring allowances (within BST tire and wheel limits), it runs BST.

From the 2026 rulebook (Appendix A)

Street: 'Mustang GT (incl. Performance Package Level 1 & 2) (2010-26)' = FS. ST: 'Mustang GT (excl. Shelby & Boss 302) (2005-23)' = BST.

Check this car with your mods →Browse all cars

Unofficial guidance verified against the 2026 SCCA® Solo® Rules — always confirm against the current rulebook before competing. Classing data cites the exact Appendix A wording it relies on.