You generally should not let a modern car sit and warm up for long; start it, wait 15–60 seconds, then drive gently, using a bit more idling only in very cold weather or to defrost.

Quick Scoop

For most fuel‑injected cars built in the last few decades, extended idling is unnecessary and often counterproductive. Oil circulates and lubricates the engine within seconds, and driving under light load warms everything (engine, transmission, exhaust) faster than sitting in place. Long warm‑ups mainly burn extra fuel, add emissions, and can increase carbon buildup, while your cabin still warms more quickly once you’re actually moving.

When you should warm it up (a bit)

There are a few cases where a short warm‑up still makes sense.

  • Very old cars with carburetors: These can need 2–3 minutes of idling so the mixture and lubrication stabilize before driving.
  • Extreme cold: When it’s well below freezing, 30–60 seconds of idling before you roll, plus gentle driving for the first few minutes, helps fluids reach a good operating range.
  • Clearing ice and fog: Let it idle just long enough for the heater and defroster to clear the windshield and windows; that’s a safety issue, not an engine requirement.

For comfort, many people still idle longer simply to get into a warm cabin, but that’s a personal trade‑off against wasted fuel and pollution.

Why “10–15 minutes” is outdated

The old advice to let a car idle for 10–15 minutes comes from the carburetor era, when engines needed more time to stabilize and oils were less capable in cold weather. Modern engines use electronic fuel injection and better oils, so they’re designed to be driven shortly after startup, with the owner’s manuals often recommending driving off gently instead of extended idling.

Enthusiast and mechanic discussions echo this: many drivers just wait long enough for idle to settle, seat belts to go on, and any infotainment system to boot, then drive normally but avoid hard acceleration until the temperature gauge starts to rise. Some mechanics even warn that long idling increases fuel dilution in oil and carbon buildup in emissions systems over time.

Latest chatter and forum vibes

This has become a small “myth‑busting” trending topic every winter, with car blogs, YouTube channels, and repair shops repeatedly telling people to stop long warm‑ups. Forum threads on r/AskMechanics and brand‑specific communities are full of replies along the lines of “start it, scrape the windows, and drive gently—don’t just let it sit there for 15 minutes.”

You’ll still see some nostalgia posts from people who grew up idling older trucks for ages, but the consensus for modern commuter cars is clear: brief idle, then easy driving is kinder to your engine, your wallet, and the air.

Practical rule of thumb

  • Modern daily driver (fuel‑injected):
    • Idle: ~15–60 seconds.
    • Then: Drive gently, avoid high revs until the engine warms up.
  • Older carbureted car or very harsh winter:
    • Idle: 2–3 minutes, or a bit more only if needed for visibility and basic warmth.

TL;DR: For most drivers asking “should you let your car warm up,” the answer today is: a short pause, then gentle driving is best—long idling is mostly a cold‑weather habit the technology has outgrown.

Information gathered from public forums or data available on the internet and portrayed here.