• We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.

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!
 
Last edited by a moderator:
T19 Howitzer Motor Carriage (105mm M2A1 Howitzer), yes this one can be called as "SP artillery", and Sd.Kfz. 251/22 (75mm PaK40 AT) as a AT unit, but I cant find other examples.
Hmm, well. For the UK we have the various 'Portee' units (a truck carrying a heavy gun in/on its bed instead of towing it). For the most part these were ad-hoc units and not permanent and usually meant for transport only. However, most of them could be fired from the bed without first unloading it. I don't think any of them were used outside of the North African campaign because tank based SP-Art (mainly based on the M3/5 Stuart, M3 Lee, and M4 Sherman) was used after that.
2-pdr and 6-pdr AT units, 20/25/37mm AA units.
Then there is the AEC Mk I Gun Carrier (aka Deacon), while this mounted a 6-pdr AT gun, it was an attempt to create the first SP-Artillery.[/QUOTE]
 
50 or 100 tons of general supply per day may not be that important for a motorized/mechanized division in Europe, but it could be a problem in Asia/Africa/Middle East/Pacific Islands and make up a large portion of the total suppy need of Infantry/Mountain/Marine/Paratroop divisions with few or no trucks.

Yes, naturally the more "militia" like the division, the larger portion of supplies needed essentials like food will become. But I was arguing for this effect and agreeing with it, saying that motorized units should require more supplies than more old fashioned infantry formations.
 
For the sake of completeness, it should perhaps be stated that the two Fuel tables are showing different things. The top table shows imports to the UK (i.e. Great Britain and Northern Ireland), which mainly came across the Atlantic from the Caribbean and later the US. The bottom table shows the global picture, which is quite different, because Commonwealth forces and territories East of Suez were supplied from Abadan in Iran (and until 1941, Borneo and Burma).

Absolutely - my reply was to a post asking about Britain's refining capacity domestically (so the bottom table showed domestic refining capacity in 'Great Britain') and about where British (to Britain, rather than to British forces elsewhere) oil came from, so it was specifically tailored around 'flows into Great Britain and domestic refining capacity). The top table is oil imports as well (all products, crude and up), while the bottom is refined products, while the top table is average weekly imports and the bottom annual refining capacity (still both in the same units). I didn't want to make the post too 'text-booky' (any more than it already was :oops:), and going into the broader picture of crude and refined oil production across all of the theatres where Britain was responsible for oil supply (or theatres like Australia, where it was responsible for half of supply for a while) gets long and complicated quick. There are more tables from the same source if you're ever interested in more info, and the book itself is available over Kindle for something like $5 IIRC, and an interesting read (if one is interested in these things of course - if not, it'd be hard going!)
 
Honestly, I'd like to see more refining techs to improve refinery output, I'd like to see the total number of building slots in states go up as now we have more items to build (refineries and fuel storage), I'd like to see a return of logistics techs which we saw in previous versions of HOI, I would like to see a difference between diesel, petrol, aviation fuel, and bunker (ship) fuel. Speaking of techs; bring back the HOI2 agricultural techs which improve food production and increase the available manpower pool.

As for Motorized artillery or mechanized artillery, or self propelled guns... Just make them cheap to research varients of motorized, mech, or armor respectively. That is how I would handle it.
 
@ Archangel85

Will planes that operate within the same strategic air region as their air base use less fuel than those that don't?
 
I am really glad to see the fuel system. Honestly, I would like to see more things from HOI3 imported, at least if they are fixed. I think that having a supply system is extremely important (a good supply system would prevent, for example, a lot of the frivolous amphibious invasions that often happen in these games). I also lean toward HOI3's approach of making it all automated, so the player doesn't have to micro-manage and also so the AI isn't at a disadvantage. The only part that HOI3 failed at, IMHO, is that it automated the system poorly. If it had done better at that, it would have been the optimal system.
 
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.

Sigh, another ahistorical idiosyncrasy in the name of some weird "balance".

Arguably motorized units should use less supplies, since horses spends most of their time eating anyway and can't really live on grass alone when put to serious work, like lugging heavy guns. I would also submit that you get your guns a fair bit further per kg "fuel" with a truck than with a horse. I get that there has to be some kind of drawback to stop spamming, but +50% supply makes no sense whatsoever.

It's like the TD's over again. Not only do they need more research than the tank, which is reasonable considering that's where they came from, but also more (comparatively rare) resources and the production cost is exactly the same as for tanks, which basically defeats the entire historical purpose of the design. It also basically makes them useless for the player. AFAIK, nobody use them, for good reasons. One would think there's a lesson to be learned here about including stuff in the game and then add penalties to them that makes them pointless. Apparently this lesson has not yet been learned.

I really wish you'd stop with this kind of nonsense.
 
It also basically makes them useless for the player. AFAIK, nobody use them, for good reasons.

Your post is otherwise solid but this statement is not true (granted, you did say as far as you know). TDs are popular in competitive MP among players who know how to play the game. You should always aim to have at least one battalion of TDs in your tank division, because even one will lift the piercing of your whole division by a lot. It's the same effect as with AT.
 
Sigh, another ahistorical idiosyncrasy in the name of some weird "balance".

Arguably motorized units should use less supplies, since horses spends most of their time eating anyway and can't really live on grass alone when put to serious work, like lugging heavy guns. I would also submit that you get your guns a fair bit further per kg "fuel" with a truck than with a horse. I get that there has to be some kind of drawback to stop spamming, but +50% supply makes no sense whatsoever.

It's like the TD's over again. Not only do they need more research than the tank, which is reasonable considering that's where they came from, but also more (comparatively rare) resources and the production cost is exactly the same as for tanks, which basically defeats the entire historical purpose of the design. It also basically makes them useless for the player. AFAIK, nobody use them, for good reasons. One would think there's a lesson to be learned here about including stuff in the game and then add penalties to them that makes them pointless. Apparently this lesson has not yet been learned.

I really wish you'd stop with this kind of nonsense.
I don't necessarily disagree, yet I'd like to argue that the food for horses are largely, if not completely, renewable and can pretty much be produced locally with little specialised infrastructure compared to fuel. The way I read the 50% increase, granted it teeters on the edge of mind gymnastics, is the entire cost of fuel production, the cost of moving the fuel and the eventual consumption.

This weird balance, I believe, is a silly result of the design decision to make the game more 'streamlined'. Speaking for myself alone here, for whatever it is worth, this game really needs more depth on certain aspects, and quite frankly can use a bit more micromanagement when it comes to economics. I know I know, I dropped the micromanagement word, burn me at the stake for it.
 
I don't necessarily disagree, yet I'd like to argue that the food for horses are largely, if not completely, renewable and can pretty much be produced locally with little specialised infrastructure compared to fuel. The way I read the 50% increase, granted it teeters on the edge of mind gymnastics, is the entire cost of fuel production, the cost of moving the fuel and the eventual consumption.

This weird balance, I believe, is a silly result of the design decision to make the game more 'streamlined'. Speaking for myself alone here, for whatever it is worth, this game really needs more depth on certain aspects, and quite frankly can use a bit more micromanagement when it comes to economics. I know I know, I dropped the micromanagement word, burn me at the stake for it.

Well, that's a fair point, or at least would be if you don't like e.g the German army on average have to feed and stable 1.1 million horses. Forage neither grows nor transports itself, and agriculture at this point in time is highly labour intensive not to mention slow. Growing sufficient volumes of forage deep into occupied, war-torn territory IMO leaves the realm of gymnastics and enters contortionism.

Also, it's not only fuel that cost moving etc. In reality, forage is way slower and more labour intensive than fuel to produce, the volumes needed are staggering and cost a huge part of your logistic capacity. To further aggravate the situation, horses have a very limited capacity for heavy work before they need significant "r'n'r" and consequently stand-ins, all of which needs food, handlers, tenders of various kinds and shelter. All of this combines to put a colossal strain on your logistics in all kinds of cascading ways. Historically speaking, there were reasons why those who had the fuel pretty quickly got rid of the horses.

As I said, I get the need to stop spamming, but this way is just daft. It's, just like the TD's, exactly 180 degrees to how things actually worked.
 
Sigh, another ahistorical idiosyncrasy in the name of some weird "balance".

Arguably motorized units should use less supplies, since horses spends most of their time eating anyway and can't really live on grass alone when put to serious work, like lugging heavy guns. I would also submit that you get your guns a fair bit further per kg "fuel" with a truck than with a horse. I get that there has to be some kind of drawback to stop spamming, but +50% supply makes no sense whatsoever.

It's like the TD's over again. Not only do they need more research than the tank, which is reasonable considering that's where they came from, but also more (comparatively rare) resources and the production cost is exactly the same as for tanks, which basically defeats the entire historical purpose of the design. It also basically makes them useless for the player. AFAIK, nobody use them, for good reasons. One would think there's a lesson to be learned here about including stuff in the game and then add penalties to them that makes them pointless. Apparently this lesson has not yet been learned.

I really wish you'd stop with this kind of nonsense.

I agree if horse-drawn transport was more efficient than trucks we would be using horses for ransport still. Also horses need to be bred to replace lost horses that takes a fixed amount of time. Arguably, the lower speed of non-motorized artillery reflects a lower amount of pack animals that don't consume as much fodder to move at infantry march speed. Motorized infantry has 0.11 supply needs vs 0.07 foot infantry which seems close to 50%. Both motorized Inf and Art need 50 trucks per batallion. So 50 trucks uses 0.04 supply (0.11-0.07). This amount (0.04) should be the increased cost of supply for motorized Art instead of 50% of baseline
 
Last edited:
Wow, finally.

As a HOI3 fanatic, I have been waiting 2.5 years since HOI4 was released (June 2016) for this update.

Talk about a delay in listening to your core audience.
 
They never changed it.
This is the Flag of the Polish Home Army which was given commands by the exiled government in London
51CQJ8KThOL._SX425_.jpg


So this is what I mean when I am asking if the Polish flag will be corrected once the exiled government is set up. Just like how France's flag becomes the Free French flag.
 
This is the Flag of the Polish Home Army which was given commands by the exiled government in London
51CQJ8KThOL._SX425_.jpg


So this is what I mean when I am asking if the Polish flag will be corrected once the exiled government is set up. Just like how France's flag becomes the Free French flag.

Why would the Polish government use an unofficial emblem of Polish partisans as their flag? They kept using the national flag IRL, and that's how it should be in HoI.

IRL neither France ever changed its flag to what we see in-game. The reason we have different flags for them is to avoid confusion. Poland however, having ended up with no Polish rump-state, does not require this compromise between gameplay and historical accuracy with its flag.