Experimental speed control¶
Alpha Longitudinal lets zoompilot control acceleration and braking instead of Mazda's own radar cruise. That enables Experimental Mode, which can stop for lights and signs. It is experimental and off by default.
Emergency braking and collision warning are disabled
Alpha Longitudinal turns off the Mazda radar. Automatic Emergency Braking (AEB) and Forward Collision Warning (FCW) stop working while it is on. Be ready to steer and brake at all times.
You don't need it for Slow for Curves or Speed-Limit Assist; both work with the car's own cruise.
compatible cars¶
It needs a compatible Mazda EPS (2022+), which can assist down to a stop, and a supported radar version. An older Mazda may qualify after an EPS swap. zoompilot checks the fitted hardware before offering the setting. Check your car. Do not force a different vehicle selection to expose it.
enable while parked¶
- Open Settings → Cruise.
- On comma 4, open alpha longitudinal. On comma 3X, the controls are at the top of Cruise.
- Enable Alpha Longitudinal and read the confirmation.
- Let the device restart and finish setup, following any Remain parked message.
choose the driving behaviour¶
The related controls are in the same place:
| Setting | What it does |
|---|---|
| Experimental Mode | The driving model plans acceleration and braking, including stops for lights and signs. The set speed is a maximum. |
| Dynamic Experimental Control | Switches between chill and Experimental Mode on its own, using Experimental Mode for stops and slowdowns. |
| Driving Personality | Sets the following distance and the gas and brake style. |
The model may drive below the set speed, miss a stop, or handle a lead car badly. Do not rely on it to stop for lights or signs; be ready to brake, even after stopping.
speed assist¶
In Experimental Mode the model often drives below your set speed on a clear road. Speed Assist raises it toward your set speed, or a lower limit from Slow for Curves or Speed-Limit Assist. Turn it on if Experimental Mode feels slow on open roads.
It works only with no car ahead. It drops the added speed a few seconds before a planned bend, stop or slowdown, and never adds speed that would take a bend past 1.0 m/s² of sideways acceleration. With some driving models it closes only part of the gap.
lead follow assist¶
Behind a steady car, the model matches its speed but mostly ignores the gap. Lead Follow Assist closes extra gap down to your Driving Personality following distance (Aggressive 1.25 s, Standard 1.45 s, Relaxed 1.75 s, each plus 6 m), never closer than chill mode. Turn it on if Experimental Mode hangs back too far in traffic. It stands down when the lead car changes, brakes, is about to slow, or is slower than about 11 mph (18 km/h).
turn on the assists¶
Both are off by default. They need Experimental Mode on and Dynamic Experimental Control off; while it is on, their switches are greyed out. Turn on Settings → Cruise → alpha longitudinal → speed assist and lead follow assist (comma 3X: Experimental Mode Speed Assist and Experimental Mode Lead Follow Assist at the top of Cruise). Leave them off while you learn Experimental Mode.
Both fade in between about 11 mph (18 km/h) and 18 mph (29 km/h), so stop-and-go stays the model's. Both stay off until 3 s after a collision warning, a predicted hard brake, a pedal press or a lane change. How the assists work
turn it off¶
Park, open the same Cruise section, and disable Alpha Longitudinal. Let the restart finish. If the car's cruise or radar stays unavailable, see dashboard errors. Do not assume the radar has recovered while a fault remains.
How experimental speed control works
Credit: Alex Frutkin (@yummydirtx) did most of the initial reverse engineering for this feature.