There’s a trend going on in Nigeria at the moment — a very disturbing one at that: most vehicles with single-core radiators, once they have an overheating episode, are replaced with dual-core options.
They call the radiators ‘single cell’ — and they replace the units with what they call ‘double cell’. Pretty straightforward, huh?
In truth (and principle), changing a single cell to double cell radiator achieves nothing, at least for regular passenger vehicles that ply the roads and are driven in a regular, sensible manner.
The logic of the Kazeem ‘mechanics’ who recommend this, however, is that, due to the ‘hot’, tropical weather of Nigeria, imported vehicles struggle with efficiently cooling their engines (with their single-cell radiators) once here.
This makes sense on the surface (especially for the uninitiated), but are single-core (single-cell) radiators inherently inferior to their dual-core (double-cell) counterparts, especially when used for regular passenger cars in tropical temperatures such as those experienced in Nigeria?
As already stated, this is as far from the truth (and reality) as anything you’ll ever come across goes.
First things first: what does a radiator do? And how does it achieve its principal mandate in a car?
Article Outline
How a Radiator Works in an ICE
An internal combustion engine (ICE) is made up of a plethora of moving parts. These parts constantly work in close proximity to each other, making the engine heat up in the process.
Though engine oil serves as a layer of protection to minimize this manner of challenge, it can only do so much. Eventually, the ultimate cooling responsibility of an ICE lies with the radiator, working in conjunction with the cooling fans (to keep the engine temperatures within spec, assuring efficiency in the process).
Explained simply, radiator coolant leaves the radiator and travels to the engine block, which is usually heated from all the combustion and action taking place in the engine.
There, it flows about the block and absorbs the heat. Now, this is where an interesting thing happens. Modern radiators are designed with fins and work with a cooling fan, right in their face.
When hot coolant from an engine gets back to the radiator, the fan activates and cools it down fast as it’s spread across the fins, increasing its surface area (the fact that the immediate surroundings of the radiator are also considerably cooler helps with the almost instant cooling the radiator coolant enjoys).
Properly cooled down, relatively cool(er) coolant is recirculated back to the engine for cooling duties, and the process continues indefinitely.
Single Cell to Double Cell Radiator: Why This Achieves Nothing
For many vehicle owners in these parts (no thanks to the wrong orientation from their mechanics Kazeems, the first thing that strikes their brains when there’s an overheating bout with their vehicles is to change from whatever radiator their vehicles had to a dual core option (double cell).
Deeply ingrained is this falsehood that merely saying it’s false won’t do much good. Here are hard, good reasons, explained in the simplest manner possible.
1. The Engine Block Size Is Fixed
Remember the summary of the working principle of the radiator and how it cools the engine block shared above? If you missed it, there’s still time enough to take a look at it before proceeding.
Now, this is what happens: coolant flows from the radiator into the engine block to cool it, when things get hotter than they should, and the heat pushes temperatures outside the regular, optimal operating range.
The engine block’s size being fixed, only a FIXED and PREDETERMINED amount of coolant can get to it at a time. A bigger radiator can hold more coolant (or water, if that’s your way) at a time, but the coolant that actually gets to the engine block from the radiator is FIXED – and just because you’re using a bigger-than-usual radiator, extra cooling WON’T happen magically.
My argument, adumbrated above, makes sense. However, if you’ve been following keenly, there appears to be a challenge with the logic…
…doesn’t more surface area on/with a larger radiator lead to more area to play with cooling, and doesn’t that increased area translate to better cooling?
Yes, it does, fortunately (or unfortunately, depending on where you stand). This reality leads to the point immediately below.
2. R&D Has Accurately Determined the Right Radiator Size
When Toyota wanted to launch the Lexus marque, more than a billion dollars and about 450 prototypes were expended. The point? The LS was tested across all manner of terrains, and components that made it to the final production unit proved to serve EXCELLENTLY, on the vehicle, IRRESPECTIVE of driving style, climate, or ambient temperature.
The same thing happens at Mercedes: more than 2 billion dollars is dedicated to research every year to make sure that the engineers come up with what will not only serve, but also brilliantly excel.
The result? Two marques that have stood the test of time.
Here’s the thing: your vehicle is best served by whatever radiator came with it from the assembly line. If a mechanic thinks he (or she) knows better, then they should be designing cars and not looking to frustrate innocent vehicle owners in their workshops.
It’s as simple as that!
3. Poor Radiator Alignment
Another evil of retrofitting a dual-core radiator into an engine bay that is designed for a single-core unit is that the radiator won’t fit properly, nor will it align as it should.
This is because the proper radiator seating of a vehicle designed with the single cell radiator in mind doesn’t properly align with the double core units, causing a misalignment when mounted.
For all such cases/units, what happens is this: the radiator usually fits towards the top, leaving the button hanging and at the mercy of whatever is there.
With such a configuration, it usually doesn’t take time before the cooling fans begin to hit what they shouldn’t. The end? Copper wires and messy attempts at correcting the challenge, attempts that shouldn’t be happening in the first place.
The ‘Double Cell’ Radiator Has No Advantage Over the ‘Single Cell’!
My daily driver for over five years came standard with a single-core radiator — and throughout my time with it (and the myriad of uses I put it to in Nigeria), it never overheated once, despite my spirited driving style.
This means that, for that vehicle, buying a bigger, dual-cored radiator would have been a waste of money, serving no true purpose.
Why is this so? It turns out the answer is much simpler than you imagined: the vehicle you’re driving was designed to use a single-celled (single-core) radiator from the factory — if that is what it came with.
The volume of coolant the single-core arrangement takes is enough to keep the engine in working state, despite the ‘hot weather’ in Nigeria. Remember, there are a lot of places even in the US with weather a lot hotter than in Nigeria, and yet, the cars there work without any overheating issues.
But Changing to ‘Double Cell’ Solved My Overheating Issues!
This is what I keep hearing every time I try to educate folks here on the senselessness of a bigger radiator on a regular car.
The truth is that NOTHING was solved: instead, what happened is that the increased fluid the dual core unit held meant temporary additional cooling power that helped with making the vehicle seem under control, for a while.
However, since the cause of the overheating issue is usually not treated, it comes back with a rare fury down the line, especially when very hot days meet spirited driving; when the water/coolant in the radiator drops; or generally, when another minor challenge, like the radiator caps, presents issues that should ordinarily not cause overheating.
So, usually, you’d be back to square one, for an issue you believed was solved before now.
Why Your ‘Single-Celled’ Radiator Causes Overheating
When your vehicle begins overheating and you have a single-cored (single—cell) radiator in it, 99% of the time, the issue is not the radiator: it’s something else: using water in your cooling system (instead of coolant), a thermostat that is stuck in the closed position, rust in the radiator/cooling system generally, a wrong/bad radiator cap or a myriad of other issues.
Hardly is your ‘single-cell’ radiator to blame for your overheating episodes!
The manufacturer who puts a single-core radiator in your car is perfectly sure that the radiator will serve the car, anywhere on Earth (BTW, cars are meant to function almost anywhere on the earth’s planet, not just where they’re manufactured).
Don’t let a local mechanic or a confused car owner tell you otherwise!
When You Truly Need a Bigger Radiator
There’s one instance, however, when you truly need a bigger radiator and when it makes sense to consider the so-called ‘dual-cell’ (dual-cored) radiators: when you’re using the vehicle in a manner the manufacturers did not envisage or when you’ve substantively modified a vehicle, over and away from what the manufacturers thought out.
For instance, because of the nature of haulage trucks (the duties they must perform and the accompanying stress on the engine), most trucks are fitted with a dual-core radiator.
If you’ve modified, say, a sedan to function as a truck, it makes sense to also modify its radiator to avoid overheating episodes.
Another example would be when you decide to use a regular passenger vehicle as a race car or on the track…since such a vehicle wasn’t designed with such a use case in mind, you’ll need to modify its radiator if its engine is to work satisfactorily without overheating.
Wrap Up
99% of the time, you don’t need a bigger radiator, and changing from a single-cell (single-core) to double-cell (dual-core) is a complete waste of money and offers no direct benefits.
However, there’s an instance where it makes sense — and this is only when you use your vehicle in a manner not intended by the manufacturer.
Anything else is a waste of time, energy and importantly, resources.
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Throttle Lan
DIY Mechanic and Freelance Auto Writer