You probably know that car antifreeze, as the name suggests, keeps your vehicle’s engine components from freezing. The simple act of keeping your coolant reservoir topped off can save you thousands of pounds on more expensive repairs.
But, engine coolant actually serves a dual purpose of protecting your engine from the consequences of heat build-up in warm conditions, too.
So, at what temperature does a car need antifreeze? Further to that point, what temperature does antifreeze stop working at, if any? You’ve come to the right place. The short answer is you need antifreeze in all conditions - scorching heat, frigid cold, and mild climates alike.
That’s because beyond temperature regulation, antifreeze safeguards against corrosion. Learn more about the benefits antifreeze brings to your vehicle below and how you can use it to enjoy peace of mind knowing your car is running well for the long haul!
Let’s start with some background information to help you understand what antifreeze is in the first place. So why do I need to put antifreeze in my car?
This fluid regulates the engine's temperature by lowering the freezing point of water in the cooling system and raising its boiling point. This goes back to the dual purpose we mentioned above. It’s a must in cold and hot weather alike.
Frozen coolant can expand and cause cracks in the engine block or radiator. On the other hand, antifreeze also helps your cooling system deal with the extreme temperatures generated during engine operation, preventing boiling and overheating.
But antifreeze also contains additives that protect against corrosion, lubricate the water pump, and ensure the cooling system operates efficiently over time.
You may be wondering, is antifreeze the same as coolant? Not quite. While the terms are commonly used interchangeably, antifreeze is the raw fluid. Coolant is the mixture after you’ve diluted antifreeze with water.
So you’ll buy antifreeze, and most often, you’ll end up putting coolant in your car. That being said, what is antifreeze made of? Here are some common ingredients:
There are many different types of antifreeze, which means that the specific ingredients can vary from formulation to formulation. More on that momentarily. For now, let’s get to the main conversation at hand: at what temperature does a car need antifreeze?
One of the most common misconceptions we see vehicle owners make is that antifreeze is only needed in the winter, or that coolant is just important during summer. Both of these assumptions are wrong and flat out dangerous. Here’s why…
Those living in the UK are all too familiar with the harsh winter weather we experience. This is why antifreeze is so important. It prevents the water in your car’s cooling system from turning to ice.
Water alone freezes at 0°C, but a 50:50 mixture of antifreeze and water can lower the freezing point to around -37°C. This can protect from cracked engine blocks or ruptured radiators and hoses. All of these would be incredibly costly repairs.
Don’t let the name fool you, antifreeze is just as important in summer. The same 50:50 mix raises the boiling point of water to approximately 107°C. This prevents coolant from evaporating or overheating.
Why does this matter, though? Because engines generate serious heat during operation. The intense temperatures associated with combustion and friction, especially in stop-and-go traffic or long drives, can take a toll on your engine.
Heat can damage cylinder heads, pistons, or gaskets. Again, these are expensive components to replace. Keeping your car’s coolant reservoir topped off is a powerful preventative measure.
Long story less long, you need antifreeze from January to December, no matter where you live. Yes, even if it’s a mild climate that never sees temperature extremes. Because remember - temperature regulation is just one piece of the puzzle.
The corrosion inhibitors in antifreeze prevent rust and scaling to keep your radiator and engine working as intended for the long haul. Modern engines rely on consistent cooling performance to meet efficiency and emission standards, too.
So whether it’s freezing or scorching outside, antifreeze is a must. But what temperature does antifreeze stop working, if ever?
While there are limits to the effectiveness of antifreeze, it typically works well in any conditions. Does antifreeze ever freeze over, though? Can it boil above a certain temperature? Let’s get into the most extreme conditions and how antifreeze handles them below.
So, at what temperature does antifreeze freeze? As we said earlier, a 50:50 mix of antifreeze and water works down to -37°C.
This is lower than any winter temperature you can expect to encounter here in the UK. Last year, the coldest recorded day was only -16°C. Our country’s coldest temperature ever recorded was -27°C.
But if for some reason you’re worried a 50:50 mixture won’t offer the protection you need, you can try a 60:40 concoction that offers protection down to roughly -45°C.
Now, let’s look at the other side of the coin - at what temperature does antifreeze boil? Remember, a typical 50:50 mix increases the boiling point to approximately 107°C at atmospheric pressure.
You might be thinking to yourself that you’ll never have to worry about this since the hottest UK days don’t get above 35°C (thankfully!). However, the conditions in your engine are much different than those outside.
That’s why vehicles are equipped with a pressurised radiator cap, which can help raise the boiling point of antifreeze further to 120°C or higher. This means you can drive stress-free in even the most intense conditions, be it:
That being said, degraded or contaminated antifreeze starts to lose its performance, and these temperature thresholds will fluctuate accordingly.
Even the best engine coolant loses its effectiveness over time, putting your engine at risk with suboptimal freezing and boiling point protection. This can be caused by:
The good news is these issues are easily avoidable. You just need to set yourself up for success by sourcing the right antifreeze and remembering to top it off or change it out altogether every so often. We’ll provide more insights below.
It doesn’t take a mechanic to maintain optimal antifreeze levels in your car. Anyone can handle this aspect of vehicle maintenance. You just need to know how to choose the right antifreeze for your make and model along with the best practices for handling refills.
But, how long does coolant last? Let’s quickly touch on the typical schedule for checking and replacing antifreeze.
Every antifreeze formulation will have its own unique guidelines, but these typically range from 2-5 years or 48,000-100,000 km, whichever comes first.
You can also take a more proactive approach by checking your coolant reservoir every month or before long journeys. The fluid should be at a healthy level between “Min” and “Max.” If it’s near or below the minimum level, there’s your answer - you need to add coolant!
Beyond discovering a low level in your coolant reservoir, there are a few other telltale signs it might be time to flush and replace your coolant, or at the very least top it off:
Any of these are an indicator that it’s time to replace your coolant. But, which engine coolant for my car is the right formulation?
It’s easy to get overwhelmed by all the different options at your disposal. So, what colour is antifreeze? And can you mix antifreeze if you’re not sure?
Always refer to your vehicle’s manual for the recommended type, such as IAT, OAT, or HOAT. Mixing incompatible formulations can cause system blockages and reduced effectiveness. So if you aren’t sure what’s already in your coolant reservoir, a complete flush and replace is in order.
You need to account for the climate you drive in as well. Colder climates call for an antifreeze that offers lower freezing points, such as a 60:40 mix of concentrate and water.
But no matter which antifreeze you’re looking for, the good news is you don’t have to look far or play the guessing game. Jennychem is here to provide the antifreeze concentrate you need.
Our brand has been the trusted choice for UK car owners and fleet managers for more than three decades. That’s because we consistently deliver a world-class product backed by exceptional customer service, all at a fair antifreeze price. Here are your options:
Each product is formulated to meet international standards. Safety, reliability, and superior engine care are the most important criteria we use in crafting these formulations. If you aren’t sure which is right for you, don’t hesitate to reach out to our customer support team.
But beyond antifreeze we have other essentials, too. Stock up on Ad Blue for sale, car screen wash, windscreen de icer, or car cleaning products like our highly touted car snow foam, traffic film remover, car shampoo, and more.
This is your one-stop shop for all things automotive care. So, protect your vehicle in any driving conditions by shopping at Jennychem today!
Before wrapping things up we want to leave you feeling confident in how to actually top off your car’s antifreeze:
Check for any signs of leaks around the reservoir or hoses after filling, and that’s it. But what if you need to flush your old antifreeze and fill it from scratch? The steps will be slightly different. You still need to let the car cool completely, then follow these tips:
From there, you can prepare your coolant concoction and fill it per the previous steps. Make sure to bleed the air as well. As for proper disposal, antifreeze is toxic and should never be poured down drains or on the ground. Take it to a recycling centre or a hazardous waste facility.
Learn more about how much coolant you need, how to dispose of antifreeze, where does engine coolant go in a car, and more in our blog.
So, at what temperature does a car need antifreeze? At this point, it should be clear that car antifreeze is not a seasonal necessity. You’ll rely on this vital fluid year-round to protect your vehicle from all temperature extremes and corrosion.
From freezing winter nights to sweltering summer days, antifreeze ensures your car operates efficiently and avoids costly damage. So, don’t settle for less than the best in your vehicle.
Enjoy peace of mind knowing you’re keeping your engine running smoothly with Jennychem’s antifreeze. Find the fluid your car needs today!
