Problems with Engines

Just yesterday I was doing some experimenting with fighters. I would take a fighter and add only one engine to it. But strangely enough, adding the regular Fighter Engine makes it the fastest, and adding the Fighter Engine III makes it the slowest. Similarly, adding two regular engines makes it slower than simply having one engine.

However, in creating fighter with something else on it (such as a weapon), the Fighter Engine III is the fastest.

What’s going on here? I first noticed weird things happening when I was designing a fighter with a bit more meat on it (armour, weapon, etc.). I wanted to make it go faster, but adding a second Fighter Engine III would slow it down. This doesn’t make much sense to me. I feel like the formulas to determine thrust are broken. Adding more engines should add more thrust, even if the ship is slightly heavier. It’s thrust to weight ratio is not decreasing, and we’re not taking into account air resistance, so why would the total speed of the spacecraft decrease?

Has anyone else noticed this?

Fighter engines lose a significant amount of thrust per unit when you add more than one in the more recent versions. This may be too extreme if adding a second thruster is creating enough inefficiency to actually cause the fighter to slow down. Does this only happen for unique builds, or lightweight fighters? I know a couple of engine IIIs is marginally better than just one if you stick a monster torpedo launcher on a fighter, but those are very heavy. Even with armor and weapon, if you were using ablative armor and rockets, it’s still going to be very light.

Using an engine I instead of an engine III and having the first be a faster fighter when nothing else is on the fighter probably just means that the thrust to mass ratio of the engine I is higher. As you found, once you add more mass to the fighter through weapons, investing in a heavier engine with more thrust becomes a better deal.

That doesn’t explain why putting two Fighter Engine I’s on a fighter makes it slower than putting one on.

A fighter has initial weight W. The engine weighs x with thrust y. A fighter with one of these engines has thrust x with weight W + y. A fighter with two of these engines should have thrust 2x with weight W + 2y. Note that the thrust to weight ratio has increased.

Maybe I’m missing something, but it doesn’t seem to add up.


Engines lose a significant amount of thrust per unit (thrust per engine, if you prefer) when you add more than one. The correct formula is closer to a fighter having thrust 1.52x with a weight W + 2y. Under those conditions, it’s entirely possible for the thrust to weight ratio to decrease.

That does make sense, according to the way the game is set up. But why is it set up that way? It seems to me that engine effectiveness drops off way too quickly. It doesn’t drop off with Frigates or Cruisers. Is this just to keep the fighter’s speed in check?

Edit: In fact, I don’t see why the top speed of the Fighter simply doesn’t change when adding more engines. Obviously it’s based on the effectiveness of the engines, but you can (for example) deck out a Frigate with engines and not have the top speed change, because the effectiveness remains the same.

The problem is that on a fighter, if I want something heavy like a Target Painter, why can’t I compensate for that by adding more engines?


Yeah, simply putting a hard cap on fighter speed similar to the caps on the other two ship classes might end up being the least painful solution to the fighter speed issue, rather than rebalancing the system to try to tweak weights and strengths to prevent any possible configuration from being so fast that nothing save antifighter missiles can hit them.

I don’t think capping fighter speeds is even necessary as long as we have a few defensive weapons with tracking speeds that are higher than the fastest possible fighter speed. With the current state of Anti-fighter missiles that shouldn’t be a problem. I am for removing the stacking penalty for engines on all ships.

The multi-engine penalty is overpunative, yes, but primarily because it causes some oddities. For example, take the rebel fighter chassis that generates 5 base power (Achilles) and strap a fighter engine 1 and laser cannon to it. You get a fighter that goes almost 3.50! Something has gone really, really bizarre with the formulas. A similar fighter with single engine and rocket launcher goes 3.85, but add a second fighter engine 1 and it goes 3.70. Not only is a rebel uberfighter still possible, it’s possible via an even less expensive and less intuitive method.

Based on my experimentation, I’d increase the weight of engines. Increased weight helps reduce the benefit of multi-engines without the sorta gamey stack penalty. This would also increase the relative speed of torpedo fighters, since there would be less of a weight gap between them and light fighters.

ie, a super light fighter has 1 base weight 2.0 weight for engine I and 2.5 weight for laser. that’s only 5.5 weight, which is why it’s so fast on such a cheap engine.

a basic torpedo bomber has 1 base weight, 2.0 weight for engine I and 15 weight for torpedo. that’s 18 weight, so it only has 30% of the speed of the superlight fighter.

if engine weights were say triple what they are now, you’d get 9.5 weight vs 22 weight, so a torpedo bomber would have 43% the speed of the super light fighter.

similarly, armor would have a smaller effect on fighter speed, since it’s relative impact on weight would be smaller.

another scenario: superlight vs double-engine light

5.5 weight vs 7.5 weight - before the stack penalty, the double engine fighter is ~45% faster.

9.5 vs 15.5 - before the stack penalty, the double engine fighter is ~23% faster.

Baseline, it just feels wrong to add more engines and go slower. Benefits shouldn’t be as overpowered as they were before, but there has to be some benefit. Finding a balance of weight and stacking would be nice, but is likely to be an iterative process.