Yokaro Solar Tire Pressure Monitoring System | $57 | Amazon | Promo code QOXLQDVY
Yokaro DC Tire Pressure Monitoring System | $59 | Amazon | Promo code N4YU8MVB
Graphic: Shep McAllister

Even if your car has tire pressure monitoring built in, it’s likely a binary system: Either your tires are fine, or they need air. But even a slight amount of under-inflation can shorten a tire’s lifespan, so a more precise monitoring system can pay for itself over time.

These models from Yokaro include four wireless transmitters and either a solar-powered receiver, or one that plugs into a car power outlet. You’ll see a real-time PSI reading for all four tires, so you’ll know when it’s time to top them up. Just note the promo codes to get the deal.