Is It Illegal to Warm Up Your Car? Puffing Laws and Warm-Up Theft (2026)
Warming up your car is legal everywhere. Leaving it running unattended with the keys inside often is not. Many states and cities ban this practice, known as "puffing," with fines typically between $50 and a few hundred dollars. The reason is theft: an idling, unlocked car with keys inside gets stolen in seconds. Here is the good news. Most of these laws specifically allow remote start, because the doors stay locked and no key sits in the ignition. In other words, remote start is the legal way to warm up. ........