What's the difference between archiving and deleting a car?

Open Mileage → Settings, tap the car, and choose Archive or Delete…. Archiving hides the car from new trips but keeps its trips in your reports; unarchive it anytime from Archived Cars. Deleting removes the car and all of its trips on every device that syncs with this one, and can't be undone. Deleting a fuel removes its price history, so cars using it stop showing an estimated cost.