One of the first questions every new autocrosser runs into is “what class am I in?” Good news: if this is your first event, you don’t have to figure that out yet. First-timers can run in the Novice class, which lets you get out on course, get comfortable, and learn how the day works without stressing over rulebooks. Once you’ve got a few events under your belt and want to start competing for class trophies, that’s when classing your car becomes worth thinking about.
When you’re ready to pick a class, here’s how it works. Your class is determined by what car you drive and what modifications, if any, you’ve made to it. The SCCA classification system groups cars together so everyone is competing on a reasonably level playing field. A lightly modified Civic doesn’t run against a full race-prepped Corvette. You run against cars built to a similar spec.
You don’t have to dig through a 200-page rulebook to figure it out either. The SCCA has a free online tool called the Classification Assistant at scca-classifier.com. Punch in your car, answer a few questions about your modifications, and it tells you your class. Start there.
The big picture: how classes are organized
Classes are grouped into categories based on how built-up the car is. Here’s a plain-English rundown of the main ones:
Street (AS, BS, CS, DS, ES, FS, GS, HS) is where most newcomers land once they’re ready to compete in a class. These are cars with little to no modifications. You can swap in aftermarket fluids and filters, change your shocks as long as they keep the stock geometry, and run any DOT-legal tire including R-compounds. Wheels need to stay close to stock size. If your car is basically stock, this is probably your class.
Street Touring (AST, BST, CST, DST, EST, GST, SST) is for sport compact cars with common bolt-on modifications, things like intakes, exhausts, and suspension upgrades, as long as the car still meets emissions standards and runs on street tires with a treadwear rating of 140 or higher.
Street Prepared (ASP, BSP, CSP, DSP, ESP, FSP, SSP) opens things up further. Full interiors are still required but race seats are allowed. Intake and exhaust are unrestricted, coilovers with adjustable perches and camber plates are fair game, and emissions equipment can come off.
Street Modified (SM, SMF, SSM) is for cars with drivetrain and suspension modifications beyond Street Prepared. Engine swaps within the same model line are allowed, turbos or superchargers can be added, and non-stock hoods and fenders are permitted.
Prepared and Modified are where the truly built cars live. Extensive weight reduction, racing slicks, and serious mechanical modifications. If you’re reading this as a first-timer, you’re not here yet, and that’s totally fine.
There are also some fun specialty categories worth knowing about. Classic American Muscle (CAM-C, CAM-T, CAM-S) is for domestic front-engine, rear-wheel-drive muscle cars and trucks. Xtreme Street (XA, XB, XU) uses minimal rules and allows for more creative builds. Heritage Classic (HCS, HCR) is for vehicles from 1974 or older. And EVX is a dedicated class for production electric vehicles.
Women are welcome to compete in any open class, and a full set of Ladies classes runs parallel to the open classes using the same rules and scoring.
What if my car is already modified?
If you’ve already put a cold air intake on, swapped your wheels, or lowered the car, those modifications may move you out of the Street category and into Street Touring or Street Prepared. That’s not a bad thing, it just means you’re running with cars built to a similar level. Use the Classification Assistant to check where you actually land before you show up.
One piece of advice worth hearing early: when you’re just starting out, don’t rush to modify the car to try to go faster. The biggest performance gain at your first few events comes from learning to drive the course well, not from hardware. Plenty of people have won their class in a completely stock car. Keep the mods in your back pocket until you have a few events under your belt.
You are responsible for your own classification
This is the one rule that catches people off guard. It is your job to know what class your car belongs in. The event staff can correct an obvious misclassification, but the responsibility starts with you. When in doubt, ask. Most experienced autocrossers are genuinely happy to help you sort it out, and it’s a much better conversation to have in the paddock than after results are posted.
Once you know your class, the next step is making sure your car passes tech inspection. That’s what the next post covers.
