brake horsepower: meaning, definition, pronunciation and examples
C1-C2 / Very LowTechnical / Specialized
Quick answer
What does “brake horsepower” mean?
A unit for measuring the power output of an engine, specifically the usable power delivered to the output shaft (before losses from the gearbox, alternator, etc.
Audio
Pronunciation
Definition
Meaning and Definition
A unit for measuring the power output of an engine, specifically the usable power delivered to the output shaft (before losses from the gearbox, alternator, etc.), as measured by a dynamometer.
A technical measurement used in automotive and mechanical engineering to rate engine performance, representing the actual power available to perform work after internal friction and accessory losses are accounted for. It is distinct from theoretical or indicated horsepower.
Dialectal Variation
British vs American Usage
Differences
The term is standard in both technical contexts. The unit itself is used identically, though American publications may sometimes use 'SAE net horsepower' (a similar but later standard) interchangeably in modern contexts.
Connotations
In the UK, 'bhp' remains a common standard for quoting car performance, often seen in marketing. In the US, 'horsepower' (typically SAE net) is more common in consumer-facing material, though 'brake horsepower' is understood in engineering.
Frequency
Slightly more frequent in UK automotive journalism. In US general discourse, simply 'horsepower' is far more common.
Grammar
How to Use “brake horsepower” in a Sentence
The engine has/develops/produces [NUMBER] brake horsepower.It is rated at [NUMBER] bhp.to measure/calculate the brake horsepower of [ENGINE].Vocabulary
Collocations
Examples
Examples of “brake horsepower” in a Sentence
verb
British English
- The workshop will brake horsepower test the classic engine next week.
- They brake-horsepowered the prototype on a new dyno.
American English
- The mechanic needs to brake horsepower test the engine. (Rare as verb)
- We brake-horsepowered the motor to get an accurate figure.
adverb
British English
- The engine performed brake-horsepower-wise as expected. (Highly artificial)
American English
- It was measured brake-horsepower accurately. (Highly artificial/rare)
adjective
British English
- The brake-horsepower figure was surprisingly low.
- They discussed the brake-horsepower rating.
American English
- The brake-horsepower output met the specifications.
- He checked the brake-horsepower specifications in the manual.
Usage
Meaning in Context
Business
Rare, except in automotive industry marketing or engineering reports.
Academic
Used in mechanical engineering, automotive engineering, and physics papers dealing with engine performance.
Everyday
Very rare. Used almost exclusively by car enthusiasts or in specialist magazines.
Technical
Core term. Used in engineering specifications, dynamometer testing, vehicle design, and performance analysis.
Vocabulary
Synonyms of “brake horsepower”
Strong
Neutral
Weak
Vocabulary
Antonyms of “brake horsepower”
Watch out
Common Mistakes When Using “brake horsepower”
- Using 'brake horsepower' to refer to power at the wheels (that's wheel horsepower).
- Confusing 'bhp' with 'hp' (horsepower) – in casual use they are often conflated, but technically 'bhp' is more specific.
- Pronouncing 'brake' as if it were the verb 'to break'.
FAQ
Frequently Asked Questions
'Horsepower' (hp) is a general unit of power. 'Brake horsepower' (bhp) is a specific measurement of an engine's usable power at the output shaft, as tested with a braking dynamometer. In casual talk, they are often used interchangeably, but bhp is more precise.
The term comes from the Prony brake, an early dynamometer used to measure engine torque by applying a mechanical 'brake' or load. The power was calculated from the torque and rotational speed under this braking load.
Brake horsepower is higher. Brake horsepower is measured at the engine's crankshaft. Wheel horsepower is measured at the driven wheels after power is lost through the transmission, differential, and axles. The difference is often 15-20%.
Yes, the term can be applied to any motor's output measured at the shaft. However, for electric vehicles, power is more commonly stated simply in kilowatts (kW) or horsepower (hp) without the 'brake' prefix, though the measurement principle is the same.
A unit for measuring the power output of an engine, specifically the usable power delivered to the output shaft (before losses from the gearbox, alternator, etc.
Brake horsepower is usually technical / specialized in register.
Brake horsepower: in British English it is pronounced /ˌbreɪk ˈhɔːspaʊə/, and in American English it is pronounced /ˌbreɪk ˈhɔːrspaʊər/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “Not applicable for this technical term.”
Learning
Memory Aids
Mnemonic
Think of the BRAKE in 'brake horsepower' not as the car's brakes, but as the 'brake' or load applied by the dynamometer to measure the engine's power.
Conceptual Metaphor
POWER IS A MEASURABLE COMMODITY (it can be quantified, rated, and delivered).
Practice
Quiz
What does 'brake horsepower' specifically measure?