What is "puffing"? Why North Texas drivers can be fined up to $500 for warming up their cars

"Puffing," leaving your car running and unattended to warm up, is illegal under Texas law and can lead to fines of up to $500.

What is 'puffing' the car? It's illegal in Ohio and can damage the engine over time

The practice of "puffing" a vehicle in cold weather might seem harmless, but there could be consequences.
The Family Handyman on MSN

What is “puffing” your car, and is it legal? Here’s the deal

Puffing sounds harmless, but leaving your car running unattended can carry legal and safety risks that vary widely across the United States.
The Greeley Tribune

Don’t become a victim this winter: Avoid letting vehicles ‘puff’ to warm up

If you head back inside while your vehicle warms up, it could disappear in a puff of smoke. “Puffing” refers to vehicles left running and unattended — usually as they warm up. The nickname stems from ...