Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. The Importance of Warming Your Car Before Driving

The Importance of Warming Your Car Before Driving

Warming Up Car Scandphoto / Shutterstock.com

Many people feel that it’s important to warm a vehicle up before driving off. This has long been the dominant school of thought, dating from when cars had carburetors and many would not run cleanly or respond properly until they reached the correct operating temperature. There was also a belief among owners of cars with aluminum engines that suggested the metal be warmed up before normal driving because of the different coefficient of expansion between steel and aluminum components.

No need to warm up

The truth is that nowadays there is no need whatsoever to warm your car’s engine before driving off. A few seconds of running is enough to get full oil pressure throughout the engine, so you can simply drive off as you would on a summer's day. This has been made possible largely through the global adoption of electronic fuel injection systems, which are calibrated to provide a perfectly combustible mixture at all temperatures, and to provide normal throttle response at all times.

It's OK to drive away

In fact, there’s a strong argument in favor of driving off immediately, and you will find that advice in most car owners’ manuals these days. You see, an engine requires very little fuel to maintain an idle speed, which means there is not much heat being generated. Without much heat, metal in the engine does not expand quickly, and the engine takes longer to achieve its design tolerances—the optimal space between moving parts. As a result, the cold engine experiences a high level of unburned fuel mixture “blow-by,” where gases blow past the piston rings and down into the oil sump, where they dilute the lubricant.

Driving away puts the engine under load, and much more fuel is needed to propel what is, after all, a pretty heavy machine. With more fuel burned in a shorter time, the engine’s components heat up faster, expand quickly, and reach their design tolerance—all of which cuts cylinder blow by to a fraction. Of course, we would not advise full-throttle, high-RPM use on a cold engine, nor would we condone lugging it. But that’s just common sense.

The only reasons we can think of why you’d want to warm your car up for some time before driving would be in icy climates, where you might want heat inside the car along with warm defrosting air to clear windshields for sufficient and safe visibility. In that situation, the additional use of fuel and risk of lubricant contamination may be worth it. Other than that, you can stop wasting fuel and time and simply get on your way.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...
P0477 OBD-II Trouble Code: Exhaust Pressure Control Valve Low
P0477 code means that the PCM has detected an abnormally low voltage reading often due to the exhaust back pressure control valve circuit.

Related questions

Q: How do I change the instrument cluster language?

Your instrument cluster can be displayed in three languages: English, Spanish, and French. To change the language that is shown, follow these steps: 1. Press the Up/Down buttons on the steering wheel until Settings is displayed on the instrument panel,...

Q: 92 Ford Ranger idles high

The first thing you'd want to do is try my video "finding engine vacuum leaks with a cigar." See if you can find a leak somewhere. It could be sucking air. If you can't find one, you want to check...

Q: Dies out at start, squealing/whistling sound, battery light comes on when it dies and wont stay running unless hold my foot the on gas.

A motor needs more fuel to run cold than it does after it warms up. There are number of conditions that can exist that will create this problem. First I will address a few things you mentioned in your question....