Why are antifreeze testers useful? Unless you’ve embraced the EV revolution already or are sticking to an old, air-cooled classic, your car will require coolant to regulate the engine temperature. Made up of a combination of antifreeze and water (often in a 50:50 split), coolant is integral to the smooth running of an engine. In the colder months of the year, having a tester in your line up of winter products is more important than you might think.
In winter, the antifreeze lowers the freezing temperature of the water, while in summer, it raises the boiling point to prevent overheating. In short, it keeps your engine working in a goldilocks temperature zone – so long as you make sure you maintain it with the best tools for the job.
If you don’t check your coolant from time to time it can start to cause all manner of issues for your engine, all of which can cost you some serious cash if you’re not careful. If your coolant freezes, it can cause serious internal damage, while an overheating engine can mean the end for seals, head gaskets and even cylinder heads. Things go deep into your engine that not even a fancy torch can illuminate them.
The best antifreeze testers at a glance:
Editor’s pick: Draper Tools Disc Type Antifreeze tester – Buy from Amazon.
Best quality antifreeze tester: Unitec 74275 Antifreeze Tester Hydrotemp – Buy from Amazon.
Best budget antifreeze tester: Gunson 77105 Antifreeze Coolant Tester – Buy from Amazon.
Affordable antifreeze testers can stop bad coolant before it becomes serious. One of these tools will spot if your antifreeze isn’t up to scratch, allowing you to change it before it does any damage to your engine. All testers we’ve chosen are easy to use, reliable and inexpensive, perfect for keeping in your toolbox. And if you need to stop your windscreen from freezing too, check out our guide on the best de-icer.
The best antifreeze testers
Editor's pick
It measures from -7 to -37 °C and being built by Draper, is a durable item designed to last a good while, and of course, many antifreeze tests.
Pros
- Great quality tester
- Easy to use
Cons
- Other options are slightly more advanced
Best simple antifreeze tester
Place the tube into the coolant chamber, squeeze the pipette to pull some coolant into the chamber and watch for how many discs inside float upwards.
Pros
- Easy to use
- Good value
Cons
- Some may find it a bit fiddly
Best quality antifreeze tester
Pros
- Great quality item
- Easy to read
Cons
- Must be careful when using
Best budget antifreeze tester
Pros
- An affordable option
- Easy to use
Cons
- Gauge might be hard to read for some
Best mid-range antifreeze tester
It comes in a plastic body which, while it isn't as well-built as the Draper unit, should last you a decent amount of time.
Pros
- Easy to use
- Trusted brand
Cons
- Build quality not as great as Draper's unit
What to consider with antifreeze testers
Truth be told, what is there to talk about with them when their constructions are so utterly simple? The market is pretty much the same as the ice scrapers one, really. So, as a priority, you probably want them to accurately measure the temperature of your coolant. So the quality of the product’s construction will be key. There is a lot of cheap options out there from unheard-of brands. But we have you covered with testers from trusted tool manufacturers.
The next is your preferred method of reading. The disc-type testers are ultra-simple, but won’t be for everyone. The Unitec tester provides an actual dial which will suit a great deal of users. The bonus feature of that device is that if you apply it correctly, it shouldn’t leak. It can be fairly easy to have one or two drops or spillages with the disc types after testing. Talking of drips, you can make your windscreen free of them with a car-based glass squeegee.
The last thing is value. Although antifreeze testers are generally inexpensive products, how much you spend if always key. The top notch brands will always charge a little more. But you have to remember that the difference in price between the things isn’t that dear. A very different field to, say, a set of snow chains.
Ryan Gilmore is the Deputy Autos and Tools Editor for Parkers, specialising in car cleaning and hand tools. A veteran car cleaner; if it details, waxes or washes he’ll be on hand to make sure it’s worth your money.
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