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HoI4 Dev Diary - Fuel Review and Motorized Artillery

Hello and welcome back for the first dev diary of 2019! Today we will update you on the state of fuel as well as show you a little something many people have wanted for a long time.

Changes and Updates to the Fuel Implementation

When the game launched, oil was used as other resources for the purpose of production. This was an abstraction done for fuel consuming equipment. We have removed this abstraction but are still using a simplified version of what happens in the real world. Oil refining was and is not as simple as simply processing it into a multipurpose “fuel,” but we felt that this simplification was necessary for gameplay and consistency of depth of detail.

We have added fuel as a resource to the top bar. With this UI element we convey a few bits of information. The numbers show the amount of time you have before being full or dry. Here the number is green and indicates that the stockpile will be full in 361 days. The numbers will become red if fuel is being lost. The green bar indicates the state of the stockpile, showing how full it is. The arrows indicate that fuel is currently being gained.

top bar fuel.png


Oil is still traded as it was previously but is no longer used in any production. Instead, excess oil is converted to fuel at an hourly rate. The trade UI has had some slight updates to take this into account. What was formerly the “production” category is now “need.” Oil now has special subcategories of this section. Active need and potential need are now represented with “A” and “P,” explained more thoroughly in tooltips. This helps give the player an understanding of how much oil needs to be traded if they wish to try and cover their current fuel needs with a constant supply from oil refining.

fuel trade ui DD.png


Refineries have also been changed from giving Oil resources to giving hourly fuel. This both makes more sense from a historical perspective and makes it easier to control how much resource is produced by refineries. Previously, tech increases could only allow for a minimum increase of a single unit of oil. This gives developers and modders much better granular control over the output of a synthetic refinery.

For countries that will not have enough fuel production during wartime to meet their needs, developing a healthy stockpile is an option. Most nations will not start with a large stockpile capacity. Stockpile potential will be reduced by economy laws for many nations. Also, increasing stockpile capacity requires some investment, and will take space away from industry through the production of silo facilities. Japan is a good example of a nation that may run into a situation during the war when their usage far outstrips their potential fuel gain, so they will need to have a decent reserve of fuel if they want to fight the US in the Pacific.

fuel_1.jpg


To help understand what is going on with your fuel stockpile and to manage distribution when fuel has become tight, we have added fuel as a special section to the logistics tab. This includes a breakdown of usage by military branch of the military and the ability to control who gets priority for fuel distribution. A special variant of the stockpile menu used for other equipment shows a breakdown of fuel consumption by day, month, and year as well as a breakdown of the state of the stockpile over time.

fuel stockpile menu.png


The logistics support company has also been changed and will help with keeping your armor fuel usage more manageable.

image (1).png



Motorized Artillery Units

When Hearts of iron 4 was released, it featured a very large number of possible battalion types that you could use to design your divisions. However, there were a few unit types that were pointedly absent. For example, if you wanted to make a motorized infantry division that was a faster version of your regular infantry division with line artillery - you couldn’t, unless you were okay with slower speed.

Part of the reason for this was the feeling that a motorized artillery unit didn’t have enough of a drawback to be a meaningful choice - it would just be better than regular artillery, and the added cost of a handful of trucks was not a major issue if you were building trucks anyway.

mot_arty_1.jpg


With the addition of fuel, that has changed. Now it is a long-term decision to motorize more of your force, and it requires more planning as your army suffers increasing penalties if you can’t meet fuel demands. So we decided to add motorized artillery units in regular artillery, rocket artillery, anti-air and anti-tank flavors. They are, by and large, identical in firepower to their horse-drawn versions but require 50 trucks each, have a roughly 50% bigger supply footprint and, of course, require fuel to run properly.

mot_arty_2.jpg


No special tech is required to unlock motorized artillery; having motorized equipment and the respective artillery type researched also unlocks the motorized unit.

That’s all for today, tune in next week when we talk about changes to research and show off the new naval tech tree!
 
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In the diary it was mentioned that excess oil is turned to fuel - where is oil expended now besides fuel production? Is it just trade? Or will there be new ways to spend oil?
 
Will you be able to destroy enemy fuel silos and/or raid them? I'm so glad motorized artillery is in the game finally. Been using a mod for that forever.
 
half-track mounted artillery, AT, or AA guns, would best be represented by an alternate set of equipment to fill out light SP artillery, SP AA, and light tank destroyer units. imo.
 
by bombing infrastructure you lower the amount of oil that can be refined as infra level affect how much is gained there

So it's a function of infrastructure level? I think I'm just trying to figure out all the buildings that convert oil to fuel, since all you said in the original post was that it was converted at an hourly rate, but not exactly what did that, other than building synthetic refineries could add to it.

One other question, is this form of upkeep going to be spread to other units? In particular, I am thinking of needing food and ammo for your riflemen, which might also help cut down on the bane of slower computers - that is, late game unit spam.

EDIT: I know food is a contentious issue that you've spoken about before in a civilian capacity, I mean it strictly as a means of restricting unit count in the late game. Apologies if that was unclear, I don't want to come across as breaking any rules, but I forgot that this could be seen as coming close to that taboo topic. If this was already discussed elsewhere or would be seen as a violation then...I apologize and pretend I just said ammo. Or let me know and I'll edit it down to that.

Thanks.
 
What about the existing motorized rocket artillery? Is it unlocked by the regular rocket tech as well?
 
Another question. I'm guessing fuel while an equipment will still be integrated as a form of supply? And will be given to your troops by supply chains instead of instantly spawning it? If so, does this means that encircled tanks will stop operating after the 48-72 hours supply grace period stops? Because that makes encirclements that much more radical now if my tanks can't push out of it.
 
No, what made you think that?
This:
index.php

The part where it says “military factories” and “naval dockyards”
If you’re being sarcastic then good, because if factories actually need fuel it means fuel becomes actually more important for landlocked nations who play infantry only.
 
This will add a strategic consideration to the game. Motorize / mechanize or not. Seize oil producing territory or not. I'm going to enjoy the challenge.

Has the synthetic oil techs been modified to account for the increased demand for oil?
 
Will giving priorty to a front also give that front priority with fuel also?
 
Have you consider to make more truck Techs, it seems strange that there is no upgrade to it, support Equipment suffers the same problem and it don't make much sense that your 30s support Equipment magically upgrade to 40s versions. These two Equipment become produce and forget which work against the purpose of production efficiency.

Also what will be the purpose of self propelled rocket artillery when there is now motorized rocket artillery.
 
Cool, but every feature that requires more longtime planning from the player will make the AI suffer even more. So I hope you are working on the AI as well otherwise the game will be getting more boring in SP.

Don't want to sound too negative but it bothers me in other games too.*Cough* Stellaris *Cough*
 
Has the synthetic oil techs been modified to account for the increased demand for oil?

Why should it? Historically synthetic fuel represented about 2-5% of all global fuel available during the war. The remaining 95%+ all was refined from natural crude oil.

It's already silly how Germany can produce 20% of the global oil through synthetics in current version of the game, that would be impossible to do in the real war. Should be considerably reduced if anything...
 
Also what will be the purpose of self propelled rocket artillery when there is now motorized rocket artillery.

There was no motorized rocket artillery icon shown; due to tech not researched yet, or not there at all I do not know.
 
Do I understand it correctly, that refineries produce fuel all by themselves, and so an industrial potent Germany with a rather competent leader could become fuel self-sufficient?
 
If oil is not used for production anymore, having excess oil means that you get positive fuel gain from oil recourse or you can sell the oil if you wish? What about having negative oil? It gives negative fuel gain from oil resource?