Brake horsepower and wheel horsepower are two types of force produced during vehicle operation. At the same time, every kind of force will have a different position and task.
In some cases, many people mistakenly believe that both BHP and WHP share the same mission. The following article will help you distinguish these 2 types of horsepower. From there, you will have a better overview of BHP and WHP.
What Is Horsepower?
Horsepower is a quantity used to measure the capacity of machines and equipment: cars, motorbikes, air conditioners.
According to the physical concept, horsepower is the work needed to lift an object. And they have the symbol HP. Horsepower was first developed by scientist James Watt in 1782. After that, more and more types of horsepower were born:
- Electric horsepower
- Mechanical horsepower
- Boiler horsepower
- Metric horsepower
In which brake horsepower and wheel horsepower of cars belong to mechanical horsepower. These are 2 common types of horsepower for cars. If you have ever learned about car engines, you will undoubtedly know these two concepts.
Many people often have confusion between HP vs WHP and BHP vs HP. You should distinguish these three concepts because each type of horsepower will generate power and perform different tasks.
What is BHP?
BHP stands for brake horsepower. It is the power generated at the flywheel near the engine. Therefore, you can call BHP the actual horsepower of the car. Through the crankshaft, the flywheel is rotated by the cylinders.
Usually, the value of BHP will be higher than wheel horsepower WHP because it is measured near the engine. When a wheel horsepower is measured, it includes power loss caused by specific components of the powertrain.
What is WHP?
WHP stands for wheel horsepower. It is the power generated at the wheels. Usually, the WHP power value will be measured using a dynamometer. To measure WHP, the driver will need to move the vehicle over the Dyno.
From there, the dynamometer will determine both maximum torque and horsepower. According to the survey results, WHP always has a lower capacity than BHP. The reason is the power consumption of other components such as clutch, transmission, differential, etc…
Currently, many people do not distinguish between BHP and WHP. They often confuse these two concepts with each other. Usually, three main points make up the difference between brake horsepower and wheel horsepower. You can refer to the three differences below.
Difference Between BHP and WHP
Frequency of change
The frequency of change is the first difference when it comes to BHP and WHP. Typically, the WHP will need to be changed more often than the WHP. Because wheel horsepower is based solely on its output power on many components.
Therefore, if your car has many accessories, the generator will need to provide more energy to create stability during travel.
Referring to horsepower, it is impossible not to mention the level of energy. A car’s WHP will have 10 to 15 percent less energy than a BHP in terms of value. In addition, if your vehicle is designed with an AWD configuration, the energy level will increase to 20 to 25% because it will need more power to the wheel.
Convenience when checking
You can see a marked difference in BHP and WHP index gauges. As you can see, it’s easier to measure the horsepower of WHP than BHP. With WHP, you will sit on the vehicle on a chassis dynamometer. Then, the dynamometer will calculate the value of wheel horsepower.
You will need to prepare a dedicated brake kit for BHP and attach it to your car’s engine. This job will be challenging if you have no experience. However, you will not need to measure brake horsepower because the manufacturer has listed them in the car manual.
Most BHP will not change horsepower during use. It only changes when your car has traveled about 100,000 miles.
Apart from that, there are many other differences between BHP and WHP. However, if you are not knowledgeable about horsepower, you will only know and understand the above 3 differences.
Because to dig deeper, there will be many topics that fall under the specialized technical category, and it will be difficult for you to understand the differences.
Cause Of The Decrease In Horsepower
The reason for the decrease in horsepower is due to the piston and cylinder wear over time.
At that time, the engine’s components will lose compression. If there is suitable compression, the power from the piston will decrease. As a result, the horsepower of the car is reduced.
Since brake horsepower is not affected by power loss, it is worth more than wheel horsepower.
Plus, to determine (the cause of the car is sluggish when accelerating) “car feels sluggish when accelerating“, you can rely on brake horsepower and wheel horsepower.
Some Frequently Asked Questions
Are brake horsepower and wheel horsepower the same?
The answer is no. Braking horsepower is the power generated by the flywheel near the engine.
Wheel horsepower is the power generated at the wheel, and each horsepower will have different duties and values.
Typically, WHP has a 10-15% lower energy level than BHP. For AWD configurations, this number can vary from 20-25%.
How to measure my wheel horsepower?
To measure the wheel horsepower of a car, you need to use a dynamometer. This dynamometer is also known as Dyno. When measuring, your car’s wheels will run on the metal rollers of the dynamometer. At this point, Dyno will calculate the amount of electricity your wheels generate during travel.
How to calculate horsepower?
We now have the formula to calculate horsepower based on torque. To calculate horsepower, you multiply the car’s rated torque by the running RPM. Then you multiply the result by 5.252. You can confirm this result because the error of the formula is minimal.
Hopefully, the article will help you distinguish between WHP and BHP. To determine them, you can consider 3 factors: change frequency, energy index, and convenience.
Also, the horsepower measurement of WHP and BHP is different. For WHP, you will not need to do much, and you just need to sit in the car to measure horsepower. For BHP, you will need specialized kits to calculate horsepower.