Let's consider that an engine has 4 states, as defined by what is happening to its speed (RPM) over time:

  • Idling: Running at a constant low speed.
  • Accelerating: Throttle is being applied; the engine's RPM is increasing
  • ???: Throttle is still being applied, the engine is running steadily at the highest allowed RPM
  • Decelerating: The throttle has been released; the engine's RPM is decreasing, eventually to return to idle.

I can't come up with a word that describes that middle state. Some suggestions I have heard:

  • Running: Doesn't work for me; I take running to mean having a nonzero RPM, so all four states are running.
  • Under load: Better, although an engine running at the highest allowed speed doesn't have to be under any load - consider a parked car with the accelerator held on the floor.
  • Cruising: Not general enough; this would work great for a plane or boat, but you couldn't describe a chainsaw running at top speed as cruising.

There are probably phrases for what I want, such as running at high speed, but I want a single word that describes such a state. The best I can do is high, but that seems too vague to me.

Context: I'm writing iPhone and Android apps to produce the sound of a chainsaw. In the code, I must keep track of the state of the chainsaw's engine so I know what to do next. For example, if we are in the accelerating state and the user releases the throttle button, transition to the decelerating state and play the corresponding sound. These words will not be used in the UI, but in my source code to describe the various states and sounds of the engine.

Any suggestions?

  • 1
    "Hauling ass"? I kid :) – Premier Bromanov Sep 29 '15 at 14:36
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    What about just "top speed"? Otherwise if the saw only has one speed then what about "steady state"? – Dan Sep 29 '15 at 14:51
  • @Rathony: No, but it's done with four-cycle yard engines such as lawn mowers and leaf blowers all the time. In fact my leaf blower has a lever that holds the throttle to maximum for you so your thumb doesn't get sore. – josh2112 Sep 29 '15 at 14:52
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    "highest allowed RPM" lends itself to redlining. Should read as "maximum RPM" if you're going with full-throttle (or just remove allowed). Also, unless you've tricked out your carburetor, I doubt it's running wide open even at full-throttle. – Mazura Sep 30 '15 at 0:27
  • related:“Gun an engine” vs. “Rev an engine” – Mari-Lou A Sep 30 '15 at 10:00

11 Answers 11


Is full-throttle the term you're looking for?

full-throttle: (going, acting, happening, etc.) at full speed or with great intensity -- Webster's New World College Dictionary

  • This is my favorite so far, and probably will be the selected answer; just want to wait to see if a true single-word is offered ;-) – josh2112 Sep 29 '15 at 14:50
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    Perhaps a little OT but I would say that names of states in computer programs should, as a matter of good programming style, exhibit parallelism, just like the analogous constructions in human language. If I were reviewing the OP's code, I'd question why all the other states are gerunds and this one is a different kind of noun. – dodgethesteamroller Sep 29 '15 at 18:02

For a single word which is specific to an engine which displays RPMs (cars, for example, usually don't provide direct control of a throttle), you are looking for the word redlining.

The term expresses the notion of taking the engine to its maximum RPM, this region of the tachometer typically displaying its numbers and lines in red rather than white or some other neutral color.

Definition of REDLINE (Merriam-Webster)

: a recommended safety limit : the fastest, farthest, or highest point or degree considered safe; also: the red line which marks this point on a gauge

However, I would not use this to describe a tool like a chainsaw or lawnmower. Here, you have a throttle lever to control, and full-throttle is the most appropriate term. Such tools typically do not have a tachometer to interact with so the user's interaction is not with a gauge but with the control lever itself.

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    As a car guy ("petrolhead" to our BrE speakers), I definitely think of myself as "redlining" my chainsaw when I hold the trigger to bring it up to maximum speed before attacking a thick log to turn it into firewood... – dodgethesteamroller Sep 29 '15 at 17:59

If you wanted to keep the gerundive form consistent I would go with racing.

  • This is almost certainly the only answer which can keep -ing and imply a high speed, but some corroboration from a dictionary would be really good to add. – Andrew Leach Sep 29 '15 at 14:37
  • It certainly meets the technical requirements of the question; I just feel like "racing" implies changes in RPM, sort of like "revving". – josh2112 Sep 29 '15 at 14:51
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    Close, but there's an implication that the engine is unloaded or running at a harmfully high speed, which doesn't fit the OP's requirement of a gerund that means "working hard at top speed." race: "to go, move, or function at top speed or out of control"; "to revolve too fast under a diminished load"; "to speed (as an engine) without a working load or with the transmission disengaged" (all from Merriam_Webster Online) – dodgethesteamroller Sep 29 '15 at 17:57

'revving' is when your engine is running fast. In an manual transmission, it's a sign that you should move to a higher gear.

In contrast, 'lugging' (a much less common word) is trying to run faster but can't because the transmission is holding it back. It's a sign to move to a lower gear.

  • As a Western AmE speaker, revving sounds a tiny bit off to me when used alone rather than as part of the compounds revving up or revving down. Either of the latter means to me a change in engine speed over time--acceleration or deceleration, in other words, which isn't the high steady speed that the OP is looking for. – dodgethesteamroller Sep 29 '15 at 17:52
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    @dodgethesteamroller It is very natural to me to use 'rev' in the context and syntax the OP is asking for "Take your foot off the gas, you're revving the engine!" or "Quit revving or change gears!" (Southern or NE AmE for me) – Mitch Sep 29 '15 at 18:00
  • As a BrEng speaker, I understand "revving" to mean "putting down the accelerator while not in gear". It makes the car make noise, but it doesn't go anywhere! – James Webster Sep 30 '15 at 14:27
  • @JamesWebster there's that too (in AmE). By presenting an answer here I'm not saying that that's the only usage 'rev' has, just that the usage I presented will work in the OP's context. – Mitch Sep 30 '15 at 14:58

It's not a single word answer unless you consider it's acronym WOT which is uncommon to hear outside of outboard enthusiasts, but wide open throttle is the first thing that came to mind. It certainly describes your situation, but I think I like @fortytwo's racing or @WinnieNicklaus's redlining better.


Wide open throttle (WOT) refers to an internal combustion engine's maximum intake of air and fuel that occurs when the throttle plates inside the carburetor or throttle body are "wide open", providing the least resistance to the incoming air. In the case of an automobile, WOT is when the accelerator is depressed fully, sometimes referred to as "flooring it."


For stationary engines, we would always describe them as being "Maxed"" or more commonly "Maxed out" when one reaches its top RPM and won't go any further.

For autos, we would describe them as "Floored" (meaning the accelerator pedal is pushed all the way to the floor).

"Revved up" would also be used in cases where you are at the desired maximum RPM, although not necessarily pushing the engine as hard as possible.

"Throttled" is another word that could describe this state, although we would more commonly use it as a verb. "I throttled the engine" means I have accelerated it. But if I say the engine "has already been throttled", normally I would mean it has reached it's maximum load.

As kind of a special case, when I worked in agriculture, we had huge diesel engines attached to water pumps for deep water wells. They would often run for days at a deafening near-maximum RPM that we would simply refer to as "open".

  • 2
    A throttle is a device that limits or restricts something - intake air flow, in the case of an engine - so I would expect a 'throttled' engine to be one running at a reduced speed. I've never heard this word used to mean 'accelerated'. To throttle a person would mean to strangle them! – nekomatic Sep 30 '15 at 8:44
  • Good point. Come to think of it, throttled could conceivably be used for any state change in engine speed, (ie. "I throttled it back") which makes it less applicable to the question. – Adam Starrh Sep 30 '15 at 12:01

Full tilt may fit.

  • Definition: at the maximum potential, speed, energy, forcefulness, etc.

Also, but a bit too long: "firing on all cylinders" (if something is firing on all cylinders, it is going at full capability).


A chainsaw with the throttle wide open is screaming, but only at or near maximum revs. If it isn't screaming it won't cut properly. Only combustion powered chainsaws scream. My small electric chainsaw is a completely different beast with a slower moving chain requiring slightly different cutting technique.


Peaking - reaching the peak speed


Ceiling can mean reaching the maximum. (Wikipedia)


This is redlining - literally derived from the red area on a tachometer.

From "Redline" Wikipedia article:

