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HOI4 Dev Diary - Fuel

Hi everyone! We have now been working on Man the Guns for a bit and it is time to kick off dev diaries again!

For those who missed it, Man the Guns is the expansion we are currently working on. The main theme is naval warfare and it will be accompanied by the 1.6 ‘Ironclad’ free update. There is no release date yet. We will let you know when we can commit to a date :)
So without further ado, rev up your engines! Today we are going to be talking about fuel...

Fuel is something we originally decided to abstract into the production of vehicles in HOI4. The reasons for this were twofold: It simplified things, making the game easier to get into and learn and it avoided issues with fuel stockpiling in HOI3 (I’ll get to that later). I still think these were worthwhile tradeoffs with the gameplay impacts it had, but some areas, particularly naval warfare, never felt right without an overall worry over a supply for fuel, which essentially drove Japanese war planning historically. This in combination with a feeling that our fans can for sure handle a little nudge towards complexity now kinda cemented the idea that we couldn’t really make a naval expansion without expanding on this area.

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(no numbers are final etc ;))

Land
Fuel is used by trucks, tanks and other land equipment with engines in your divisions. They will use much more when fighting and moving than when stationary or during strategic redeployment (in fact right now those consume no fuel, but that might change with balance work). A division carries a bit of fuel with it ( much like how supply works), so there is a short grace period if cut off. If a division is in bad supply it will refill its fuel more slowly (meaning you won’t be able to attack or move rapidly as frequently), and you might even be unable to refill at all if totally cut off. Being without fuel will negatively affect the stats of the battalions that need it as well as severely impact speed depending on how low they are.
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Air
Your active air wings will consume fuel. The amount will naturally depend on the type of plane (strat bombers love to guzzle down that fuel) but also what mission type. Planes on interception will be very fuel efficient as they only take off when there are enemies attacking ground targets or bombing etc. Transport planes on air supply missions will also be able to deliver fuel to pockets etc. When low on fuel air wings suffer big efficiency penalties.

Sea
Running a lot of active capital ships is something you will need to be careful with in Man the Guns. These behemoths will be going through your fuel stockpile like starved baby whales on the teat. To handle this and make fleets act more realistically and in a more controlled manner we have changed quite a bit here, so stay tuned for future diaries. The main point is that big fleets are costly to run and you will need to make decisions on how to best utilize them and how much to fit into the rest of your fuel use. Speaking of, you’ll be able to control who gets first dibs on fuel through prioritization just like with equipment (but we are also working on adding extra controls on top of this so you can more easily balance between the different branches of the armed forces). A fleet that is low on fuel will suffer penalties to its stats as well as operational range.


Production
Fuel is produced from unused oil, and equipment that used to use oil now no longer need that to be produced. I am currently looking into possibly adding copper or another resource in its place (and in some other places), but we will see if that ends up being a good idea or not ;) Will let you know. Anyways, if you are low on fuel there are several ways to go:
  • Acquire more oil rich states.
  • Increase infrastructure on your own oil rich states.
  • Trade for foreign oil.
  • Build synthetic refineries.
  • Lend leased fuel.
  • Capture enemy stockpiles.
  • Research improved oil to fuel conversion technologies.
  • Each unit of oil you have access to use your current techs to generate a certain amount of fuel. This fuel is then put into your stockpile for use by your forces.
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Stockpiling
Fuel is possible to stockpile, in fact it is necessary if you can’t guarantee a steady stream of produced fuel during wartime. The size of your national stockpile will depend on the number of states and their infrastructure, your economic law and if you have built Fuel Silos. This is a new building that takes up shared slots and will probably provide the majority of your stockpile space. It is also a building that can be damaged from bombing etc. which in the worst case could lead to a loss of fuel. Capitulating enemy neighbors is also going to be a good way of acquiring more fuel as it will work just like seizing their equipment stockpile in that respect.

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HOI3 also had stockpilable fuel, and there it was quite a problem. As a beginner you did not know how much (or even that you had to) stockpile and as an experienced player there was no issue in making a stockpile big enough that you wouldn't ever have to worry. In HoI4 we are aiming to force a tradeoff between building up your industry and increasing the stockpile (have to spend civilian factories to get more oil from trade instead of building more factories) as well as trying to keep the total amount you can stockpile within reasonable bounds. Our goal is fuel as something you’ll need to consider for all your operations and playing it really safe will mean less industrial output in the long run.

Since I bet this will be the first question, fuel is going to be in the free update, but there will of course be features in the paid expansion that tie into it (stay tuned for more diaries!).

We are still working on all things fuel so I’ll wrap up here. Hopefully it gave you an idea of what we have done and are planning to do. I’ve saved some interfaces talk for future diaries, and also, be aware that many things could end up changing based on gameplay feedback. Rest assured though, I’ll keep you updated on stuff like that in these diaries up to release. This is not really anything out of the ordinary, but I usually keep systems like this that need long term balance and iteration for later. Fuel however ties into a lot of future topics, so I wanna make sure you are all clued in :)

Now for something completely different...
I assume nobody has managed to avoid having their mailbox fill up with fun updated privacy policies and things related to the new European General Data Protection Regulations (GDPR). During all this a really smooth looking lawyer dog in the smartest little suit I have ever seen came over to visit us from Brussels. He told us there are a bunch of regulations we too need to follow in our games… so to make sure we remained Good Boys in the eyes of the law we have added a couple of things to Hearts of Iron IV. The most important is to include our Privacy Policy in the game and making it easy to find.
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Legal texts are long and boring and nothing has really changed in how we do things. So I would rather spend my time answering questions here and writing the rest of the diary, so I will refer you to check it out ingame or here if you want to.

What I would rather talk about is how gathering data from players is useful to us. Because it is. Super useful! Without telemetry we would be resorting to guesses and risk only the most vocal minorities to be heard. For example, telemetry data is one of the major things we look at for deciding what nations to develop focus trees on. We get data on how popular difference choices are for focuses, letting us spot balance issues or unpopular paths that could use some love and care. We can spot if new out of sync errors are introduced in multiplayer in graphs and get crash reports automatically uploaded to help us fix problems easily. All this, combined with a scoopful of forum reading, is what helps us steer this ship, so thanks for helping :)

Oh I almost forgot, because we had to make the GDPR compliance hotfix we managed to sneak in a fix you guys have been asking for. We solved an issue for a case in China (similar things could also happen elsewhere) when a nation had both a takeover and inherited wars (like when seizing ownership in the Chinese power struggle) and was at the same time occupied. As a Japanese player this would lead to the less than happy situation of seeing your occupied areas flip back to the enemy and leaving troops cut off from supply. We also fixed a crash issue that was reported in some big mods. The patch should be releasing shortly.

Next week some of the team will be on summer vacation (including me!) but Bratyn is going to be here to talk about all the awesome stuff he has been doing with Britain, so don't forget to tune in!

  • Fuel for Thought
  • The Rise of Legal Pooch: GDPR always strike twice!
  • How we sell your personal data to Big Pharma for cocaine in 3 easy steps!
  • We have updated our fuel policy
  • Starved Baby Whales on the Teat is actually the name of the HoI 4 punk rock band playing at PDXCON 2019
  • Fuelling your conquests
  • Some of your data is belong to us, if you are okay with that
  • Help us help you help us
  • Our coders call it Nightmare Fuel actually
  • Adding fuel to the fire that engulfs the world
  • Anyone doing a dramatic reading of our privacy policy may request one Admiral to be added to the game
  • Proudly Introducing Gasoline Mana
 
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Question 2:
Does the strategically redeploy function consume fuel? I would assume so, cause units are transported by rail.
(Or were trains powered by coal?)

No, no fuel cost for strat redeploy. Germany actually used steam powered trains because of resource situation from what I've gathered.

I think I would rightly assume that lack of fuel for tanks would negatively impact stats like soft attack, speed and breakthrough, as the tank can make less use of it because its moving around less. But what about its "inherent" stats like armor and piercing that would be constant, will they be affected?

yeah all stats. a tank that cant move effectively cant really be where it needs to be etc.

This looks good. Open question, because it's something I haven't thought about but could well be in the game already - do states overseas need to be supplied by convoys to still give out supplies? For example, if Italy is at war against the UK, are the troops in Ethiopia still in supply even if the convoys don't get there? I honestly can't remember, and don't have time to check in game. If not, it's something that should be considered. If it is in, can fuel be stored overseas as well?
yeah that requires convoys. There is a certain amount of local supply as well though of course
 
how to go previous patch 1.5.3? this not working at all, stuck in loading 90% if got that 10% and game start there is no divisions to see.

quite pissed off, played couple evenings!

in the patch sticky there are instructions for how to do it. you can first try clearing your local files in the launcher as it sounds like there might be some wierd issue like that
 
Well, we usually talk about stuff as early as we can. We can always delay talkign about it, but its hard to go early. Also nobody likes to get stressed at work for marketing deadlines. If it fits it fits, otherwise we show stuff when we feel ready :) but I do agree it would have been a great date

Not for me it's not!
 
If we are not at 100% storage capacity say for example 50%. Will the fuel be evenly split between different depots? So that if we loose land we gradually loose fuel or could we block certain depots from being used (temporary - I know one could destroy them but I'd like to deactivate them), so that for example Germany has the fuel Depots of France, Poland and Benelux but only uses German ones because those are the most secure ones?
 
How do synthethic refineries currently work? Do they still produce oil, or fuel directly?

Also, if oil is no longer used to build equipment, will it have any other use? Or is functionnally fuel gain divided by a coefficient that depends on your tech?
 
Let me ask some questions:

1. How do we refine oil into fuel? Do we need to assign factories (or even refineries) or all the surplus oil just turn into fuel by themselves? I ask this because for countries like China not being able to refine fuel on an industrial level was a huge problem back in WW2. If no refineries are involved, I hope it is modifiable.

2. Is it possible to mod fuel-ish resources into the game? Namely, can I create an equipment type and specify its consumption rate for a given unit under stationary, moving and fighting stances respectively? I understand that ammunition and rations are abstracted into supplies (rightfully so), but some may want to go for the extra mile and have it directly represented.

3. Since supply system is also under rework, would it be possible to mod supply depots which stores all kinds of equipment into the game? So it's like silos but for other equipment.
 
I love the introduction of fuel to the game. And I’m sorry to be so trivial, but as a petroleum engineer, I have to comment on your terminology.

Please don’t use the term fuel silos. No one in the oil industry uses that term. We call them tanks; or, if we are being formal, storage tanks. A single physical location containing multiple tanks is called a tank farm.

However, while tank farm would work for me, it might be hard for most players to relate a tank farm to fuel.

The term fuel tank will at least let the player know that it’s fuel related, but that term usually refers to the fuel tank on a vehicle, not a 50 foot high storage tank.

Fuel storage site would at least let the player know it’s fuel related, but thats kind of long.

Fuel storage would probably be the term that you want to use for the building in a state that stores fuel.

And before anyone criticizes me for wanting the proper terms to be used, consider two things:

1) The word silo is simply the wrong word. A silo is a structure used to store fodder or grain (or missiles), not liquids. A tank is a structure used to store liquids. You can look those terms up in any (US) English dictionary.

2) Using the correct term is extremely important for immersion. After all, we call them bombers; not bomb dropping planes (or BDPs), or bomb carrying planes (or BCPs), or bombdroppers.
 
I love the introduction of fuel to the game. And I’m sorry to be so trivial, but as a petroleum engineer, I have to comment on your terminology.

Please don’t use the term fuel silos. No one in the oil industry uses that term. We call them tanks; or, if we are being formal, storage tanks. A single physical location containing multiple tanks is called a tank farm.

However, while tank farm would work for me, it might be hard for most players to relate a tank farm to fuel.

The term fuel tank will at least let the player know that it’s fuel related, but that term usually refers to the fuel tank on a vehicle, not a 50 foot high storage tank.

Fuel storage site would at least let the player know it’s fuel related, but thats kind of long.

Fuel storage would probably be the term that you want to use for the building in a state that stores fuel.

And before anyone criticizes me for wanting the proper terms to be used, consider two things:

1) The word silo is simply the wrong word. A silo is a structure used to store fodder or grain (or missiles), not liquids. A tank is a structure used to store liquids. You can look those terms up in any (US) English dictionary.

2) Using the correct term is extremely important for immersion. After all, we call them bombers; not bomb dropping planes (or BDPs), or bomb carrying planes (or BCPs), or bombdroppers.


What about "fuel depot"?
 
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Will be changes in supply system (calculation using previous consumes in the path, distance?).

Could say something more about how is fuel refined?
 
Nice, I'm quite pleased with they ways that you added fuel to the game. Looking forward to hearing more about the patch and DLC :)