There has been a lot of debate on warming up your car in the winter. In fact, there are lots of articles posted on social media every winter telling you how bad it is. That you are harming your car. Most of them read like this one from the Weather Channel
The problem is none of these articles really tell the whole truth. Most of them are biased by the environmental impact versus the actual damage done to your car.
Indisputable reason for not warming up your car
The only reason no one can argue against letting a car warm up is theft. Unless you have a remote start, you are leaving keys in an unlocked running car. This is begging for someone to steal your car. The only way to prevent that is to sit in your car while it warms up. What’s the point of sitting in a cold car waiting for it to warm up. Every other reason for warming up your car seems to be up for debate.
Will Warming up Your Car Harm the Engine?
There’s been a lot of debate on engine damage caused by warming up your car. Depending on how you look at things it’s possible. However highly unlikely.
Letting your car idle for extended time does wear out the engine. However, extended means more than 10 minutes. Which is true no matter what the temperature is. Running your engine is wearing it out. Although it’s not wearing your engine any more than if you were driving the car. In fact, since there is no load on your motor it’s less wear, than driving.
A few articles have stated that letting your car idle slows down the warming up process. This, in turn, allows your engine to run rich for longer. Thus potentially running the risk of letting gas wash the cylinder walls down and diluting your oil. While all of this was possible in a carbureted car with full choke on. It doesn’t happen in modern-day cars. They are designed to produce the least amount of emissions as possible. Thus the computer monitors any rich condition and limits it to what’s necessary for the engine to run.
Is there a benefit to warming up your engine
Letting your car idle for a few minutes when it’s cold is a good thing. It gives your oil a chance to get to all the places in your engine. Even with full synthetic 0W-20 oils, oil is thicker when it’s cold. Thus it moves slower. Which, runs the risk of your engine not being fully lubricated when you take off driving right away. Even giving your engine a minute or two will help make sure your engine is fully protected by oil.
Of course, it’s not just your oil that needs to be warm when driving. New cars use your antifreeze in the radiator to help warm up the transmission fluid. Thus cold antifreeze equals cold transmission fluid. This can be hard on a transmission.
The most important benefit of warming up your car for a few minutes? Your personal comfort and safety. No one drives very well when they are shivering. Nor is it easy to see out of your windshield if it’s frosted over on the inside. Just a few minutes of idling to get some heat inside your car will help you be more comfortable and make sure you can see out of your windshield.
The Downsides to Warming up Your Engine
The biggest downside to warming up your car is the gas mileage. Letting your car idle for even a couple minutes can burn a lot of gas. Your gas mileage will go down. Of course, winter blended fuels don’t help your gas mileage either. This, of course, is amplified the longer you let your car warm up. Which means a few minutes is OK. 10-20 minutes is a waste of gas.
Of course, if you are an environmentalist warming up your car is a huge no, no. You are putting our car exhaust that is not necessary. That is unless you like being warm when you drive. Of course, considering cars have fewer emissions once they are up to operating temperature it’s debatable as to which is worse a few minutes of idle time or running your car at higher RPM’s when it’s still running rich. So we will just say if you are truly worried about global warming and it freaks you out. Don’t warm your engine because there is a slight chance you could be giving a few trees a little extra CO2 to breath.
Last and most important as we’ve already mentioned. Letting your car warm up does lead to an easy target for a thief. If you are going to leave your car warming up for more than a few minutes in your plain view, it’s an easy target to be stolen. Consider having a remote start installed or having a second key.
Should you warm up your car?
Personally, this author is cheap and hates spending any money he doesn’t have to. That said, my car gets warmed up when it’s really cold out. Having driven old cars that require scraping the inside of your windshield, a few minutes of idle time is worth it. What’s really nice is getting into a car that’s warm on the inside when it’s well below freezing outside. At the very least let your car warm up while you scrap your windshield. Even one minute to let things warm up in just your engine can save wear and tear on the engine. Of course, you don’t need to let your car warm-up for 20 minutes. It’s still good to give your car a couple minutes to warm up before you go driving around town in stop and go traffic.
Conclusion
Ignore all the hype on how dangerous warming up your car. There are plenty of people like Jalopnik that will say the same thing. As long as you don’t leave your car idle for more than a few minutes. There is nothing majorly wrong with warming up your car in the winter. With your comfort being well worth starting your car a few minutes before you have to leave. So go head warm your car up and forget all those articles written by overzealous environmentalists to scare you into driving a cold car.