Check oil monthly
Pull the dipstick monthly with the engine cool. Wipe it, reinsert it fully, and pull it again to read the level. Top up to the upper mark with the manufacturer-recommended grade. Running an engine low on oil destroys it quickly.
Tire pressure and tread
Check tire pressure monthly with a gauge. Inflate to the manufacturer's recommended pressure, found on a sticker inside the driver door jamb. Check tread depth with a quarter — if Washington's head is fully visible above the tread, the tire is worn out and needs replacement.
Wiper blades
Replace wiper blades every six to twelve months or whenever they begin to streak. Worn blades reduce visibility in rain to dangerous levels and replacement is cheap and tool-free.
Lights
Walk around the car once a month with someone who can confirm the headlights, taillights, brake lights, and turn signals are all working. A burnt-out brake light is a common cause of rear-end crashes and a frequent traffic stop.
Scheduled service
Follow the manufacturer's maintenance schedule in the owner's manual. Modern cars require less frequent service than older ones but the recommended intervals exist for a reason.