I have noticed that the Enterprise very often travels at speeds like warp 2, 3, 5, and so on. This is especially true in the early seasons. It almost seems that the warp speed they choose to travel at is a measure of the "importance" of whatever is going on.

Is there an in universe reason why don't always travel at, say, warp 8 or 9? It seems that they could cut their travel times down significantly.

I understand that there are limits to the engine. And that travelling at the higher ends of the warp 9 scale approaches those limits. But surely there are high speeds that are not near the limits.

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    TL;DR - High warp damages the engines.
    – Valorum
    Jun 20, 2014 at 19:06
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    For the same reason why it's not a good idea to drive your car at it's top speed every time.
    – Monty129
    Jun 20, 2014 at 19:59
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    @Monty129: "I understand that there are limits to the engine. And that travelling at the higher ends of the warp scale approaches those limits". Travelling at warp 2 when they could just as sensible travel at warp 7, 8, or 9 is like driving at 15 when you can sensibly go at 70.
    – nomen
    Jun 21, 2014 at 23:40

2 Answers 2


Imposed Speed Limit

Well, it was established that certain areas of space are negatively affected by warp drives, and so a speed limit of warp 5 was imposed except in extreme circumstances.

What happened to warp drives destroying the universe?

Fuel Economy

Just like a car, there is a cost to running at higher warp. The warp drive doesn't create energy out of nothing, it requires fuel ( Dilithium or anti-matter). You could cruise around at Warp 9 everywhere you wanted, but fuel economy would suffer.

Wear and Tear

Running the warp drive at maximum is like redlining the engine in your car. Doing that for sustained amount of time results in an engine failure.

Forced to extend her shields around the vessel to protect it from asteroid collisions, the Enterprise burned out three of four lithium crystals, forcing the crew to supplement with battery power. The fourth crystal subsequently failed, overstressed from handling all of the ship's power. ref memory-alpha


What is better, to arrive in the middle of the night at a destination, or when the captain will be awake and on the bridge? How critical is it to get there immediately (usually, not very). When there isn't a hurry, why rush to get there in 10 hours when you can get there in 2 days without any ill effects?

  • But they're in space. There's no resistance to oppose their inertia. Energy is force times distance, and once they're at speed, force is 0.
    – nomen
    Jun 20, 2014 at 19:24
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    @nomen The warp drive isn't moving the ship, it's moving space itself. It needs to continually stretch the space behind the ship and compress the space in front of it to maintain relative speed (the ship only appears to be moving faster-than-light to observers outside the warp bubble) so constant energy input is necessary. Jun 20, 2014 at 19:33
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    Good answer Jack. I would add training and leisure time to that answer. If you rush from one 'task' to the next you're creating an environment for mistakes. There needs to be time to process, evaluate and train between missions. They also need to have a little 'down time' to recharge as well.
    – Morgan
    Jun 21, 2014 at 16:48
  • While this holds for higher warp factors, I fail to see how it is relevant for lower ones. With the exception of going to pick up Troi's mother, why would the Enterprise D ever go at Warp 2 (10x the speed of light) when Warp 5 (213x c) is over 20 times faster? Space is big! By comparison, Warp 9 is over 1500c, so it's not like they are taxing the engine at Warp 5, and fuel consumption isn't that big (<1000x more than Warp 2, but 1000x less than Warp 9). For comparison, Warp 2 is 5 months from Earth to Alpha Centauri, Warp 5 is 7 days.
    – user11521
    Sep 13, 2015 at 6:12
  • @user11521 you might go warp 2 to move slightly faster than something else moving warp 1.5 Nov 20, 2018 at 2:43

While this is speculative and not based in cannon, in physics and in economics it's commonly considered the case that continuing to increase an output requires exponentially more input, to a point where the expense is greater than the return. See Law of Diminishing Returns

Take thermodynamics as a specific example. When hot and cold meet, the rate of change between the two is fastest when the two temperatures are furthest apart. While ultimately they will balance, it can take longer for that last degree to even out than the first 50. Similarly in a 70 degree room, it takes more energy to raise an objects temperature from 100 to 101 than it does from 70 to 71.

So one may conclude that the energy cost to travel at higher warp speeds is similarly higher, and thus running at warp 9 would burn up the crystals 3 or 4 times as fast as running at, say, warp 6. These are made up numbers, but they illustrate the possible cost and cause.

  • But they're in space. There's no resistance to oppose their inertia. Energy used is force * distance. Once they're at speed, force is 0.
    – nomen
    Jun 20, 2014 at 19:26
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    @nomen: It takes power to create and sustain the warp bubble. That's what the warp engines do: they create and sustain a warped section of space which allows the ship at its relatively constant speed to travel increased distances. The big energy sink isn't moving the ship, it's constantly bending spacetime around the ship such that each second of travel takes it further.
    – Jeff
    Jun 20, 2014 at 19:42
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    And faster speed requires stronger bubble requires more power. Plus it's not correct that there's no resistance in space. The vacuum of space is not perfect. Photons from stars fly every which way (making solar winds and thus solar sails), and other gasses and solid particulate matter also are in space (100-300 metric tons land on earth daily: universetoday.com/94392/… )- they're just spread REALLY thin because there's not enough gravity to hold them together. Jun 21, 2014 at 14:42

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