Should You Warm Up Your Car When It’s Cold?

If you have your own car, you’re sure to have heard the advice to warm up your car before driving when it’s cold. It sounds like a reasonable thing to do, but have you ever stopped to consider whether or not it’s true?

​We’re here to tell you that the answer is…

A Big No

That’s a definite no. Contrary to the myth you may have heard, warming up your car when it’s cold does not prolong the life of its engine. In fact, it does the opposite. Your engine’s cylinders and pistons are stripped away of oil in the process. 

How? Let’s first discuss the process of combustion within your engine so you can better understand why you may be unwittingly hurting your car.

Your internal combustion engine works using pistons and cylinders. Pistons compress the mixture of air and vaporized fuel. This mixture leads to a controlled explosion when ignited. This is what we call a combustion event, and it all happens within a cylinder. 

These pistons and cylinders are quite important for the usability of your car, and they’re the exact ones that you strip the oil from when you unnecessarily warm up your car when it’s cold.

Mythbusting

So how come so many people are misinformed about whether to warm up your car when it’s cold? How did this myth start? 

For a myth to confuse so many people in an information-fueled world, there must be a ring of truth to it. And there was, at least when carbureted engines were still the norm. 

Here’s the story: You need your fuel to evaporate to make combustion possible. However, when the engine is cold, that is difficult for gasoline. Thus, it is difficult to achieve the right ratio of air and vaporized fuel needed without some kind of regulation. Carburetors used to take care of this problem for us. 

This engine makeup cultivated the practice of warming up the car when it’s cold. As in current car engines, carbureted ones mix gasoline and air to make vaporized fuel to run. However, unlike the current engines, carburetors lack the sensors to tweak the amount of gasoline. 

So for carburetors to work properly, the engine had to be warmed to a normal running temperature to avoid the possibility of the engine stalling.

Luckily the fuel injection method solved this problem for us. So while our cars engines have moved into modern times, it seems our general car know-how hasn’t kept the same pace.

If you have a carbureted engine, should you warm up your car when it’s cold? Yes. However, we haven’t built cars with carburetors since the 1980s. 

While the knowledge of warming up your car was passed on to all the young and eager new car owners, the carburetor, the reason for warming the car up, was left in the past. 

What Actually Happens

Fuel injection solved the troubles that the carburetor could not. It pumps more gasoline into the mixture to compensate for the cold. This allowed the engine to continuously run well despite the temperature until it reaches about 40°F, but closing one door only opened another.

According to Stephen Ciatti of the Argonne National Laboratory, a mechanical engineer specializing in combustion engines, “putting extra fuel into the combustion chamber to make it burn can result in some of it staying on the cylinder walls. 

Over an extended period of time, this gasoline can wash the oil off of the cylinder walls if you run in idle conditions. This significantly reduces the life of engine components such as piston rings and cylinder liners. 

Aside from washing away lubricating oil, your engine also gulps up extra fuel in its efforts to run your engine at such temperatures. Imagine the waste of precious gasoline just to strip your engine off its oil.

What To Do

Instead of wasting fuel and harming your engine with a myth, the fastest way to warm up the engine of your car is by driving it. Five to fifteen (15) minutes of driving is enough. Take it easy on the first part, then expect things to normalize after. 

Driving will help your engine switch back to the normal and engine-safe ratio of air and fuel faster than the warming up that old, carburetor-using folks believe. In fact, performance cars use a graduated rev limiter to help this process by inhibiting you from getting full RPM before the engine reaches the right temperature. This ensures that you will not in any way harm your engine through accidental misuse. 

In case you’re still not sure what you should be doing to start your car properly when it’s cold, we’ve made a simple three-step process for you. Starting this method right away will relieve your engine of unnecessary strain and you of unnecessary stress. So, here’s what to do:

1. Start the car. 
2. Check if your defroster is working.
3. Get going.

And that’s all!

Another way to help your engine on those cold mornings is by using an engine block heater. This aftermarket product can help your car’s fluids hit the right temperature, making the heater and defroster ready for a winter drive even before starting your car. 

Instead of using more fuel, the engine block heaters use an electrical element to preheat engine fluids for an easier engine start.

Trucks are the most common users of engine block heaters, though they can be retrofitted to other vehicles. They are inexpensive considering that they reduce the natural wear and tear of engines due to cold weather. 

For More Info on Everything Car, Call American Auto Care/ASR

Automotive Service and Repair of Murrieta can help you properly prepare for those dreaded cold winter mornings, whether it be knowledge or equipment to help keep your car running smoothly.

Ask your trusted mechanics at ASR about anything having to do with engines, or any other car part to help keep your car in its top condition to give it the long life it deserves.

​

Remember that proper vehicle maintenance will help you keep your running at its top condition, so not only will you feel safe driving it, but you’ll also help your car keep its value. 

American Auto Care/ASR of Murrieta not only can help you learn the proper cold morning routine for your vehicle, we also deliver quality car maintenance services for a price that won’t break the bank.