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What Size Radiator Do I Need For My Truck?

What Size Radiator Do I Need For My Truck?

It is critical to select a suitable size radiator for your truck. Radiators come in variety according to size.

You have to choose according to your requirement. For example, if a radiator is large, it will bother you in two ways.

Large-size radiators require more energy to run and occupy unnecessary space. They are expensive too. 

What Size Radiator Do I Need For My Truck? For selecting the accurate size truck radiator, we should measure the truck’s dimension. So, we will first measure truck length, width, and height where we have to install the radiator. Finally, we will use a BTU calculator to choose the right-sized radiator.

What Size Radiator Do I Need For My Truck?

Radiators in trucks or automobiles are used to cool the engine. They keep the temperature at its optimal point.

Continue driving produces heat, and radiators cool down the motor by heat transfer phenomena.

They require to maintain a good balance of heat for a pickup. Radiators come in a variety of sizes. There is a rule. Small for small and large for large.

The larger the truck size greater will be the radiator size. It does not give us authentic and specified information. We have to make measurements. 

Measure truck dimension 

Take a measuring tape, a notepad, and a pen. First, you have to measure its height, length, and width and convert these into square feet.

BTU calculators

BTU calculators give a trouble-free approach to estimate the size. It is actually the measurement of heat that requires raising the temperature of one pound of water by 1 degree Fahrenheit.

Thus, while measuring temperature, water thickness will be at the highest point that is 39 degrees of Fahrenheit.

Before going to calculate, the following measurements should are necessary.

  • Length
  • Height
  • Width
  • Total area on square feet 
  • Outdoor temperature
  • Desired inside temperature
  • Difference between two temperatures

Now you are on the step of measuring heat output and finally the size of the radiators. You can install two or more radiators if you want to install small size device on different walls of the pickup.

20 BTUs are essential per square foot. When you have measured its dimensions i-e length, width, and height in square feet, calculate BTU.

1 square foot needs 20 British thermal units. Multiply the number of square feet by 20. Then, choose the size according to your calculations. 

Chart showing BTU and trucks dimension and how they are related 


(Depth × height × length)

Output in watt Output in BTU per hour
55 ×1600 ×250 800 2500
55× 1800 × 150 850 3000
50 × 1000 ×500 890 3000
50 × 1500× 450 1400 7500
100 × 1500 × 240 1350 7320

Standard sized radiators

Radiators also come in standard size. They have a range from smallest to largest. You can select from them. First, you must have proper knowledge about your radiator requirement. 

The small-scale radiators come in size between 800mm × 1500mm. Large size radiators come in a range of 600mm × 2500mm. So it is upper and lower limit. In between this range, other sizes are also available. 

Steel panel radiators have a range from800 × 2000 to 1500 × 500mm. Cast iron radiators come in large sizes. 

Radiator building material affects radiator size

The building material used in the construction of radiators can be of 4 types, Iron, stainless, mild steel, and aluminum.

All these have different features. The greater the potential heat output, the smaller will be the required size.

Research and evidence prove that an aluminum radiator gives maximum potential heat output. Therefore, they are considered master radiators.

Their heating time is minimum and, their ability to retain heat is peak. So they can provide peak potential BTU even with smaller size. So, therefore, we can say, for aluminum radiators, we can buy smaller sizes. 

Cast iron radiators

There is a general concept that cast iron radiators are a wastage of money. It is not correct. They have unique features.

Although they take extra time to heat and consume more energy, They have the maximum capacity to retrain heat and, they come in large size. If you have enough space then, purchase them.

Steel radiators

They are big-sized radiators and have moderate output. They are considered average radiators. They provide heat quickly but unable to retain it for a longer time. 

Factors that affect BTU requirements and truck radiator size

The above calculations for British thermal units are theoretical. Actual readings always differ because a lot of other factors have their roles.

Type of airflow

Two categories of airflow can be possible

  1. Downflow 
  2. Crossflow


There are tanks in the downflow radiator one is attached to the top, and the other is fixed to the bottom of the radiator core.

Coolantmoves from up to the down direction that is from upper tank to lower tank. Its requirements are high. They give low BTU per square foot per hour.

Cross flows

Here, two tanks are on the opposite side, right and left. As a result, they provide high BTU per hour in comparison with the downflow. 

How radiator placement affects the size?

There are two possible arrangements:

  1. Rear-mounted
  2. Horizontal mounted 

Rear-mounted: They are very suitable for small pickups; they are located on the backside of the dumper. The drawback is they are difficult to install and handle. They add more complexity. They also need extended routing of water hoses. 

Horizontal mounted: They occupy much larger space, require more BTU in their operation. In addition, they come in large sizes. 

Outside temperature

If you travel all-time in high-temperature areas, then consider this factor too. However, if you travel to different temperature zones, then ignore this point.

Continuous high temperature increases more energy consumption which a large size radiator can provide. However, for cold regions, a small size than theoretically calculated are enough. 

How single panel and double panel radiators affect size?

Single panel radiators mostly use for small-size trucks. Their heat-producing efficiency is comparatively low.

They have merely a one-sheet which is form from steel. They provide a small surface area. They are not a good option for large-size pickups as they have small surface areas.

Double panel products have a large surface area due to having two single Steel panels and two layers of convector fins. They require low power for producing more heat. 

Trucks insulation

New pickups heat up quickly and best able to retain heat. With the use and passage of time, insulation affects badly.

Old pickups require more energy expenditure than new ones. If you want to buy it for a 5 to 6 years or older heavy good vehicle, pick up a large radiator. 

Final thoughts

What size radiators do you choose directly depends on BTU requirements. British thermal units depend on trucks’ measurements.

The greater the number of BTU required larger will be the radiator’s size. 

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