Will a Bigger Radiator Help Keep Your Car Cooler?

There are so many performance-enhancing and mechanical upgrades that you can get for your car. Depending on what car you drive, there could be more than a few gimmicky purchases that don’t help. Sometimes it’s hard to tell what makes a difference and what doesn’t, but it would make sense that having a bigger radiator helps to keep your car’s engine cooler, right? Swapping to a larger radiator might not be on your list of maintenance or upgrades that you’re going to do to your car, and there is probably a reason for that.

What a radiator does

The radiator is an essential part of your car, but many people may not understand precisely what it does. Internal combustion engines produce a lot of heat, and the car’s cooling system is responsible for keeping the mechanical components at operating temperature. If the motor gets too hot, it can cause severe damage, and the radiator plays a big part in making sure things stay cool.

Stacks of car radiators with their grilles on a factor floor
Radiator grills stacked on the floor of a factory, by Zoltan Glass | Zoltan Glass via Science & Society Picture Library/SSPL

Thermodynamics in action

The radiator works because coolant, yes, that annoying fluid you may have had to refill once or twice, circulates through the engine and into the radiator. An axial fan pushes air through the radiator, helping cool down the cooling fluid that will return to the engine. In the process, heat is effectively removed from the engine.

The surface area of the radiator allows the air to cool the fluid. So it would logic out that having a larger radiator, with more surface area, could help more liquid cool even faster. Having a larger radiator is definitely a gimmick that you can find in many aftermarket parts shops, but that doesn’t necessarily mean that it is actually helpful.

Taxi car overheating in NYC
Car overheating | Spencer Platt/Getty Images

Size doesn’t really matter

If you are looking to upgrade your radiator, getting a larger one probably isn’t the answer. Instead, the type of radiator that you have makes more of a difference than the overall size of your radiator. There are several different types of radiators, and the type of radiator can change how effective your car’s cooling system is. So really, when it comes down to it, size isn’t what matters.


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Of course, there are a few ways that having a different sized radiator makes a difference depending on what specific vehicle your drive. Overall, putting a giant radiator in your car isn’t going to help keep your engine that much cooler, but upgrading to a system that is more effective will.

For your standard commuter car, you shouldn’t be particularly worried about your car overheating. Chances are if this is a problem, you are driving a performance-oriented vehicle that has been modified. Consumer cars are designed with the appropriately sized radiators, so overheating isn’t a typical problem.