BHP vs WHP (Difference between Brake & Wheel Horsepower)


Comparing different horsepower measurements

BHP and WHP, are both abbreviations that need to be defined! A lot of people who don’t spend a lot of time driving around have no idea what the difference is between BHP and WHP.

In this article we are going to look into what both of these mean, what are the main differences between the two, and which one is between is a better measurement between Brake Horsepower and Wheel Horsepower.

In short, the main difference between BHP and WHP is the fact that BHP is measured at the engine, WHP is measured at the wheels.

What is BHP?

BHP stands for Brake Horsepower, is calculated by measuring the amount of power produced by the motor without any losing power produced that is caused by other factors such as
• water pump,
• cooling system
• transmission
• alternator
• other components like steering pump and differential.

The purpose of measuring BHP is to give an accurate measurement of how much power is generated by the engine itself. It was first used by engineers when developing steam engines for use in factories and locomotives etc.

What is WHP?

WHP is wheel horsepower, basically the amount of power your vehicle is putting to the ground. WHP tells us what we can expect on a chassis dyno, or in real-world conditions.

WHP is a more accurate representation of power because it takes into account all the power losses between the engine and the ground, such as gearbox efficiency, drive train friction/losses, front-wheel drive power loss, etc.

How are BHP and WHP Measured?

BHP is brake horsepower, and WHP is wheel horsepower. BHP is measured at the engine, WHP is measured at the wheels.

In order to get from BHP to WHP, you have to take into account things like the efficiency of your transmission (if it’s automatic or manual), the drivetrain (FWD or RWD), and any accessories like your water pump, power steering, A/C compressor, alternator, etc.

So if an engine makes 50 BHP, and has a 20% efficient tranny with a 10% loss in the drivetrain (typical for FWD or RWD with no LSD), then you’ve got 50 x 0.2 x 0.9 = 9 WHP

Which is better Brake Horsepower or Wheel Horsepower?

For many people, the answer to which is better BHP or WHP? Depends on one thing: How fast do you want to go? The fact is that WHP is a more accurate measure of the power your car actually makes while the BHP rating is more of an estimate.

The truth is that you don’t actually know how much horsepower your car has. You can only measure it after it’s finished and been run on a dyno machine. Before then, you’re only guessing as to how much power it will make. So if you need to choose between WHP or BHP, it’s best to choose WHP.

Is WHP the same as HP

The short answer is yes, whp and hp are the same. Whp or wheel horsepower is the amount of horsepower delivered to the wheels. Horsepower is typically a measurement of engine power, but in this case, it refers to the amount of power transmitted to the wheels and not to the flywheel.

A vehicle’s engine efficiency can vary from car to car due to different drivetrains and setups. So, sometimes it may be beneficial to measure power at the wheels rather than at the flywheel.

How do you convert BHP to WHP?

The formula to convert BHP (brake horsepower) to WHP (wheel horsepower) is to multiply the BHP by 0.85. This means that you would need to multiply the brake horsepower of a vehicle by 0.85 in order to get the wheel horsepower.

Brake horsepower refers to how many shaft rotations are made per minute, which is how engines are tested, while the WHP refers to how much power is actually used to move the vehicle.

It’s common for some vehicles to be rated at a higher WHP than their BHP because they’re more fuel-efficient and therefore don’t lose as much power between the engine and axle.

Conclusion on WHP vs BHP

The general consensus is that both are good for different reasons, and which one you lean towards should be based on your own unique needs.

Jimmy

Jimmy Mitchell is an electric vehicle aficionado who has been following the space since Tesla first hit the scene. A longtime proponent of sustainable transportation, Jimmy was one of the first to buy a Tesla 3 as soon as it came out. He loves nothing more than helping others learn about and enjoy the benefits of electric vehicles. When he's not evangelizing about EVs, Jimmy enjoys spending time with his family and travelling throughout south east asia

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