Why You Don't Need to Let Your Car Warm Up In the Winter

Every winter morning I do the same thing:

Start the car at 8:40.
Curse that it's one degree outside.
Let the car warm for 10 minutes.
Leave at 8:50 (it's awesome living 10 minutes from work!).

But not yesterday.

My radiator broke, and letting the car run means coolant all over the ground. Coincidentally, the same day someone shared an article on Facebook about this very thing.

It argued we only need to run our cars for 15-30 seconds in the winter.

WHAT?! I've been warming up the car in the cold for, like, 10 years. So as I brought in my broken radiator'ed car to the mechanic (shoutout to my 1997 Saturn with 200,000 miles on it! you sexy beast), I asked him.

"I've been idling my car in the winter for 10 minutes before I go to work. Literally EVERYONE on the block does this. Is it necessary?" I asked.

"Nope," he said. "15 seconds to get the oil circulating and pressure up. Maybe 30 seconds when it's really cold."

Then this article came to me from the Washington Post. I am sold. You do NOT need to idle the car in the winter.

Main points:

Older cars (think 80s and earlier) that relied on carburetors DID need to warm up to work well, according to several auto industry experts. Warming up carburetors DID allow them to give the engine the correct mix of air and fuel.
BUT. Starting in the 80s and 90s, carmakers did AWAY with carburetors. They probably don't exist in your car! Sensors now do what carburetors used to.
If you drive a "modern car" (like my 1997 Saturn, you sexy, sexy green animal, you), all you're doing is wasting gas.
DO let the car idle for 15-30 seconds to allow the oil to circulate throughout the engine, since oil is cooler and thicker in the cold. Oil needs to heat up and thin out, which takes 15-30 seconds. After that, you can drive it!

Still not convinced? Here's an updated article with even more reasons.