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What's the difference between a motor and an engine? (2013)
- mikece 2y agoOne thing that jumped out at me is that the word engine, in its historic understanding, would apply quite well to the Rube Goldberg drawings of overly complex contraptions to do various tasks... which means it would also apply to most enterprise architectures which are similarly overly complex.
- rkagerer 2y agoYeah, it doesn't look like the alternative definition "instrument of torture, an apparatus for catching game, a net, trap, or decoy" has lost utility just yet.
- JohnFen 2y agoThis was fascinating to me. Also, I was apparently using my own personal definition of "engine" that was somewhat different than the other modern usage. To me, a "motor" is something that translates energy into motion. An "engine" is something that translates energy into work. So a motor is a kind of engine, and uses of "engine" in knowledge work is an analogy.
- dylan604 2y agoYour engine definition is interesting as we have phrases like database engine and other software based uses of the word.
- Tagbert 2y agoI think, once you get past mechanics, the definitions are going to diverge pretty quickly.
- nemo44x 2y agoYou used the word "translates" instead of "transforms" or "transfers". Is there a particular reason for that?
- foolswisdom 2y agoThat actually fits well with the origin of the words (as described in the article). And it makes sense because engine is sometimes used metaphorically (?) (as you note), while motor is not.
- LinAGKar 2y agoWhat would count as "work" under that definition (that's not motion)?
- JohnFen 2y agoYeah, the distinction is a bit fuzzy. I can come up with some examples, such as certain kinds of pumps that don't involve moving parts. But when I think of things I call "motors" and "engines", I admit the distinction appears arbitrary (but clear nonetheless in my mind). For instance, if there's a device that moves things as a component of a larger machine, I'd call that device a "motor", but am likely to call the larger machine an "engine". And to go back to the pump, I'd call the device that moves to push the liquid a "motor", not an "engine", for no good reason. As with much of English, this "rule" has enough exceptions as to question whether or not it should be called a "rule". I put "rule" is scare quotes because what I was originally describing is decidedly not a rule at all, just a description of how I tend to use those words.
- msravi 2y agoMy personal definition of "engine" had to have something combustible inside it that caused motion. So fossil fueled cars and buses and rockets had steam engines and internal combustion engines and rocket engines, but electric cars like tesla have motors!
- hypertele-Xii 2y agoSteam isn't combustible? What about the Stirling engine, powered by heat gradient and air?
- jabl 2y agoSteam engines and Stirling engines are both examples of "External Combustion Engines", whereas piston engines and gas turbines are examples of "Internal Combustion Engines" (ICE).
- cm2187 2y agoBut you don't say "jet motor". I think it's probably like pork vs pig. They are technically the same but the language has come to use one vs the other in a different context (food vs animal).
- vlachen 2y agoI think that's just a matter of jargon. As an aircraft mechanic, I heard and spoke the phrase "Pull the motor on aircraft..." Many times. We used engine and motor interchangebly on an engine thrust powered aircraft.
- actionfromafar 2y agoAren't there large areas of the anglophone world where "motor" = electric motor and "engine" = something that burns fuel to turn?
- JohnFen 2y agoIn my part of the US, anyway, gas car engines are usually called "engines", but calling them "motors" is not that unusual and wouldn't raise any eyebrows. There are a few auto repair shops around here that even call themselves "motorworks".
- hunter2_ 2y agoAlongside motorworks there are countless others: motorcycle, motorboat, motorway, motorhome, motel (hotel that you motor to), motor oil, motor mounts, etc. etc.
- geodel 2y agoAnd Car used to be called Motor Car for as long as I remember in my country.
- JohnFen 2y ago> motel (hotel that you motor to) When I was a child, I remember seeing some such accommodations calling themselves "motor hotels" or "motor lodges".
- hunter2_ 2y ago"Motor inn" is still quite common.
- fuzzfactor 2y agoObviously named accordingly since vehicles like this all contain an engine ;)
- jabl 2y ago
- dylan604 2y agoIn modern day usage, I would never refer to an electric motor as an electric engine or just engine, but I don't know why. Maybe just because I have never heard nor seen it used referred to as electric engine. So it just sounds/feels weird to say/type it. That is the opposite from definitely referring to an ICE as a motor. English is just weird.
- ozim 2y agoIt is weird if you look from top down view like organized “Queens English”. Truth is people just made stuff -bottom up- if some phrase was used it just spread out or not. It is that even rather close neighbors might use different names or phrases for the same thing or same names for different things. Even if at school you learn a generic version.
- dylan604 2y ago> Even if at school you learn a generic version. On a slight tangent, I took 3 years of Spanish in school in Texas where they taught Castilian Spanish instead of Mexican Spanish. You know how often I speak to Castilian Spanish people vs Mexican Spanish people...in Texas?
- bryanlarsen 2y agoSimilar problem in Canada where Parisian French is often taught in English Canadian schools rather than Quebecois.
- willsmith72 2y agoi dunno, when i hear french teachers at english schools in bc, that accent is far from parisian
- fatnoah 2y agoAs the resident of a northeastern US state, relatives on one side of my family grew up speaking French, so naturally I took French in high school. I was embarrassed when I still couldn't speak French with the family and had to resort to English when visiting Montreal. I was, however, vindicated later in life when I visited France and was able to get by without English.
- tofof 2y agoMy uncle worked at Estes, the hobby rocket company, for many years. He was always a stickler about calling the black powder propellant sources "motors" and indeed older motors are labeled such. [1] He insisted they were not engines as they had no moving parts and would always correct me when I said "rocket engine." He eventually explained that rocket engines exist, but they are engines with valves and pumps and use liquid fuel (e.g. the Saturn V's F-1 engines), while solid rockets (e.g. Estes' products, or the shuttle's SRBs) are simply motors since they merely consist of burning propellant and a nozzle. Indeed the wiki pages for the F-1 and the SRB are consistent in calling the former engine and the latter motor. However, at some point since he retired, Estes transitioned to calling them Engine/Motors [2], and now, the primary labelling Estes uses calls them Engines, though Engine/Motor is still printed on the cardboard casing itself. [3] Interestingly, the Spanish, French and German on the motors still use motor, as Motor, Moteur-Fusee and Raketenmotor, respectively. Because of that upbringing, I have since treated the words to mean that a motor is something that provides force of motion (thrust or rotation) - it may or may not also be an engine, as in the rocketry examples. An engine is a contraption with moving/interacting parts that uses energy to accomplish some goal - that goal may (F-1, car engine) or may not (cotton gin, search engine) be the propulsion of the contraption itself and what it's attached to. That said, as a child I made no such distinction, hence the frequent corrections. I am happy to recognize that in common vernacular they are usually synonymous, though it would still sound strange, I think, to call something a 'search motor' (edit: however, see comment by yau8edq12i !) or a 'graphics motor' just as it would be jarring to encounter 'servoengine'. 1: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitAz7uOjIvVoDiDxNHms8nAMtd2kjU2e2rNq0hxxIvWKXI6WpoQLeSOQ7_WTc_fXtrmvn7MIRSaQ0l2HdIeKtoueORegSfay1azQnxFLZcWR3OSpESqjmtTzd1swbP75arPP9EGwu-ynE/s1600/Old+Engines.jpg https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi... 2: https://www.apogeerockets.com/bmz_cache/f/f8ecac9604d017a5c7ad9cb1fa48ea39.image.700x473.jpg https://www.apogeerockets.com/bmz_cache/f/f8ecac9604d017a5c7... 3: https://estesrockets.com/products/b6-4-engines https://estesrockets.com/products/b6-4-engines
- cenamus 2y agoAs for German, there isn't really an equivalent for engine, even combustion engines are called (Verbrennungs)Motor.
- yau8edq12i 2y agoFun fact: the French word engin still retains its original meaning of contrivance, contraption. But we still translate "search engine," which refers to this archaic English meaning, as moteur de recherche ("search motor").
- fvdessen 2y ago“engin de recherche” could have worked as well, but “engin” also has a taken negative connotation of something that doesn’t work well
- Suppafly 2y agoPretending that they are anything but synonyms now is ridiculous and I'm glad the article pointed out that they are used that way instead of pretending that the older definitions still have merit like so many prescriptionist folks do.
- czl 2y agoMotors primarily convert electrical energy (or fluid/air pressure in the case of hydraulic/pneumatic motors) into mechanical motion. Engines primarily convert chemical or thermal energy into mechanical power. The term is also applied metaphorically to a central component that drives a process or system. > Pretending that they are anything but synonyms now is ridiculous and I'm glad the article pointed out that they are used that way instead of pretending that the older definitions still have merit like so many prescriptionist folks do. So you are ok with having your opinion about this recorded in online forum's database motors and easily discovered by users of Google's search motor?
- SAI_Peregrinus 2y agoRocket motors don't convert electrical energy into anything. Motorways are ways (roads) for automobiles, most of which which use petroleum products for their power. Motorcycles use gasoline to produce their mechanical motion. I view "motor" as a subtype of "engine". An engine drives a process or system, either literally (producing power from some fuel or other energy source) or figuratively (as in Google's search engine). A motor is a type of engine that changes the momentum of some object.
- mhink 2y agoWhile I think I agree with your definition of "engine", I'm not sure I agree with the idea of "motor" being a subtype of "engine". To me, a "motor" is a specific part of a system's powertrain: it's the part which converts some other type of energy into kinetic energy for the purposes of moving the system. On the other hand, an "engine" is a self-contained system that establishes some kind of stable feedback cycle to perform a task. With that in mind, a car's internal combustion engine is the motor of the car, since that's the place where chemical energy becomes kinetic energy, which results in motion after being transferred through the drivetrain. If you take the same exact engine out of the car, mount it in some fixed position, and rig it up to generate electricity, I wouldn't technically call it a "motor" anymore, because it's not acting to move the system it's a part of. (That being said, I probably wouldn't split hairs here, since the engine was originally designed to be a motor. But you see my point.) Importantly, this lets us fit diesel trains into our definition: they use diesel engines to generate electricity, but electric motors to actually make the train move. In an old steam-driven train, It also addresses the question of what to call the part of a model rocket that makes it go up. It's the part of the rocket's powertrain which converts chemical energy into kinetic energy that moves the system. It's a *motor*. --- So, with all that said, an interesting point is that the terms "motor engine" and "engine motor" both make sense, but don't mean the same thing. "Motor engine" describes an engine designed to perform the role of motor (as opposed to a "generator engine"), whereas "engine motor" describes a specific kind of motor (as opposed to a "chemical motor").
- mp05 2y ago>> Today, the words are virtually synonymous. Ehhh that's a stretch, unless we're talking Real Housewives type of "lay people". As I understand it (within an engineering context), a "motor" converts electrical energy to mechanical energy, and an "engine" takes thermal/chemical/some other form of mechanical energy and outputs mechanical energy. But it's confusing because I've changed the "motor" in my old Honda when I was a teenager. So while I agree there is some nuance and blurry lines, not sure the two words are quite "interchangeable".
- CamperBob2 2y agoIt seems reasonable to say that a motor is something that moves something else, while an engine is also something that moves something else but uses internal moving parts of its own. We can just leave it at that. All engines that involve physical motion are motors, but not all motors are engines. That seems better than making arbitrary distinctions regarding which type of input energy is being transformed into which output type. It would also be compatible with the OED definition mentioned in the article, as well as terminology used in rocketry.
- johnwalkr 2y agoI agree with this but I also wouldn't blink if someone used one or the other term unless there was a specific context where it was important.
- CamperBob2 2y agoYep, pretty pointless hill to die on.
- fuzzfactor 2y agoWouldn't want to anger a mean biker who was a member of a violent enginecycle gang ;)
- SAI_Peregrinus 2y ago
- inetknght 2y agoThe way I see it: A motor produces locomotion. It makes other things move. An engine produces power. Locomotion can be derived from power but isn't required to. A train locomotive might be referred to as a "locomotive engine". A car with an internal combustion engine moves from power generated by that engine. But a car with electric motors does not have an engine because power is not produced there. Power is produced elsewhere and then stored in the battery. Locomotion is produced by consuming the stored power. Of course, that's just my interpretation of the two words without referring to a dictionary.
- saalweachter 2y agoA tractor was originally a "traction engine", to distinguish it from the steam engines you would haul around with horses to power equipment.
- upwardbound 2y ago> An engine produces power. Locomotion can be derived from power but isn't required to. By this definition, is a fuel cell an engine? https://www.energy.gov/eere/fuelcells/fuel-cells#:~:text=A%20fuel%20cell%20uses%20the,electricity%2C%20water%2C%20and%20heat https://www.energy.gov/eere/fuelcells/fuel-cells#:~:text=A%2....
- LinAGKar 2y agoOr even just a barrel of fuel that's lit on fire to produce thermal energy
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- 8372049 2y agoIn my language, everything is a motor and the "engine" root is only used in engineer.
- Dulcynder 2y agoNot sure about your particular language but I'm appending to this comment to say that plenty of people saying latin languages don't have a word for engine are probably wrong. Motor comes from latin "that which moves something", for example in italian that's "motore". Engineer is "ingegnere", someone who uses "ingegno". So I'd argue the word for engine, in italian at least, is "marchingegno", which has somewhat a bad connotation (overly complex). I'm unsure if this was always the case. Translators give "contraption" which fits my understanding for the english word. So a generic word for a complex machine that does something. That said it's not used and you'll never hear someone talking about the marchingegno in a FIAT panda
- panzi 2y agoMy native language is German. We only have the word Motor. Thought engine is just the 1:1 translation of it, but apparently not.
- ajuc 2y agoSame in Polish. "Silnik" is both motor and engine. You add second word to specify the kind (electric, combustion, stirling, steam, ...).
- yakshaving_jgt 2y agoI think silnik translates most directly to powerplant in English, given that the root word is siła.
- amszmidt 2y agoPower plant would be elektrownia. The suffix -nik is a common one that one can append to almost any noun to indicate that something or someone doing something, e.g. robot, robotnik (worker). So silnik translates to motor/engine, not powerplant.
- yakshaving_jgt 2y agoIn English, you can use the word powerplant in a more abstract sense, e.g., to refer to the engine or motor of a car. It doesn’t only specifically mean the large industrial building which generates electricity, as I believe elektrownia does. I think your note about the -nik suffix is congruent with my point. A silnik is a thing that is doing/making siła. To clarify, I’m perfectly aware that if I tell someone in Poland that I have a problem with my silnik, I’m referring to the engine in my vehicle. But in this discussion here, I’m talking about the most direct translation.
- amszmidt 2y agoAs someone fluent in both English and Polish (being my native language), I cannot see how silnik and a fixed place where power is generated, specifically connected to a network where that power is put out (i.e. powerplant) have anything in common. The only direct translation of the word is really just engine/motor, one can often use the word motor to mean silnik as well.
- mikewarot 2y agoIn my usage, Engine is generally something that consumes gasoline (sometimes Diesel) and generate rotational power and lots of exhaust gas and heat. I almost always use the term motor for an electromechanical machine that turns electrical into mechanical power. Like all words, there's ambiguity to it.
- garyfirestorm 2y agoSame here. Maybe it’s how I grew up. Gas engine Electric motor Never understood why people used the word motor to describe the engine.
- jandrese 2y agoThis is how I use it as well. It is a convenient way to encode a hint about the power source into the base word. A slight refinement of the language and a good example of how languages evolve over time to better suit the era they are in.
- 0x0203 2y ago> “Engine” is from the Latin ingenium: character, mental powers, talent, intellect, or cleverness. And thus we get a common root for the words engine and genius. Fascinating.
- smitty1e 2y agoIf asked to craft a definition, I would offer that motors are electrical and use magnetism to induce rotation on an armature. Engines are chemically driven and use some flavor of combination to rotate a shaft.
- coffeedan 2y agoIs a bicycle an engine (or a motor)? It is a machine with moving parts that converts power into motion.
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- leecarraher 2y agoWas the article written by an llm difference engine? In that it failed at discussing the differences of the two and really just regurgitated the etymologies and ancient definitions of the two terms with no insight about modern usages. My quick difference as a matter of opinion only is that engine is related to carnot some heat cycle creates enables work that can be turned into locomotion. Motor is a superset, and is some system, process or machine that turns potential energy into kinetic energy. That is my opinion, of which i am open to, in fact very interested in reading others. Unfortunately this was not that article, instead you get a brief history lessons on words, with the thesis that some word's meanings change over time (allow me to pick my jaw off the floor) and don't worry about delineating the two terms because they pretty much mean the same thing. Not what i was expecting from mit engineering.
- nottorp 2y agoIt's from 2013 so I guess this essay-ish style of writing is one of the sources present day LLMs have been trained on.
- leymed 2y agoMy understanding engine is a device governed by laws of thermodynamics, whereas motor is based on electrodynamics. Always thought calling car engine a motor is incorrect, shouldn’t be used interchangeably. In my experience machinery would be common name for both in engineering terms, not daily usage.
- ClumsyPilot 2y agoEngine converts lower form of energy, like heat, into higher form of energy, like kinetic, at a loss. It’s shifting up Motor converts equivalent forms of energy, or down, at very high efficiency. Electric to kinetic
- dpifke 2y agoA related bit of terminology I recently picked up[0] is "electric motor" vs. "electric machine", with the latter being preferred when the machine can function as either a motor or a generator (as is the case e.g. for most brushless DC motors). [0]: I've been working my way through this book: https://www.amazon.com/Design-Brushless-Permanent-Magnet-Machines-Hendershot/dp/0984068708 https://www.amazon.com/Design-Brushless-Permanent-Magnet-Mac...
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- ecjhdnc2025 2y ago> The OED lists a second definition of “engineer” as well. “It is synonymous with the older usage meaning ‘artifice,’” says Fuller. “An engineer is an author or designer of something, a person who contrives a plot, a schemer.” A definition one can only hope will soon pass from common usage. I am not at all sure why. This is an enormously valuable concept: that plots require both participants and also people who do not just direct it or order it, or even just design it, hands off (often called "the architect of the plot"). They need people who are there from start to finish, like an author is; involved in every corner.