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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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Technically, in a historical sense, yes. But what is represented in game is tank based not mech based. Both Germany and the US (not sure about others) had a wide range of Half-Track based SP-Artillery and AA (not so much on AT).
Ahh...
Apparently I have not been fussy enough. :eek:
Thank your for helping me. ;)
 
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.

Why not add potential to all other resources, as need of resources for all assigned factories, including not fullfilled or destroyed. You got empty space for it anyways.

Fuel need for factories is also interesting idea, as one of limiters for non-stop factory-building through the war. And they DO consume fuel in real life, both itself and for logistical needs. But too complex for balancing purposes, so it will probably look better in another update, in complex with other limiters for (over)growth.
 
Nice job. I was wondering when motorized arty would finally be added, as it's been requested for a long time now. The inclusion of fuel makes this a sensible addition.

Interesting that you also confirm that oil is no longer used as a resource for building anything, but simply as a mechanic for generating fuel. Does this mean that ships no longer require any oil to build either?

I am still waiting for an answer on whether carriers can be converted (back) into battlecruisers, however, or whether it's just a one-way street.
 
Fuel need for factories is also interesting idea, as one of limiters for non-stop factory-building through the war. And they DO consume fuel in real life, both itself and for logistical needs.

From my reading during prewar and WW2 most factories could be run on coal or other electrical energy (hydro), and most industrial logistics was handled by rail ( powered by coal ).

So while some factories ( mainly in the USA ) could run on oil and handle all logistics with trucks (fuel), it was far from something everyone did.

I think it would be better represented as some kind of "Law" or "Decision" mechanics where you can opt in or invest to increase the fuel dependency of your industry to boost production output, but doing so require X fuel per factory in upkeep. For example I doubt Chinese factories were running on fuel in the 1930s.
 
Im a little confused, if oil is no longer used in production, what is the meaning of excess oil? Wont all oil now be considered "excess"?? Can someone help me understand o_Oo_O
 
So oil is no longer used in production? Building planes will just need rubber and aluminium?

Correct, oil is out of production. But the planes are not going to be very useful without fuel, which comes from either oil or synthetics. So the actual answer is planes still require oil.
 
I am pretty sure that during prewar and WW2 most factories could be run on coal or other electrical energy (hydro), and most industrial logistics was handled by rail ( powered by coal ).

So while some factories ( mainly in the USA ) could run on fuel and handle all logistics with trucks (fuel), it was far from something everyone did.

I think it would be better represented as some kind of "Law" or "Decision" mechanics where you can opt in or invest to increase the fuel dependency of your industry to boost production output, but doing so require X fuel per factory in upkeep. For example I doubt Chinese factories were running on fuel in the 1930s.


Mostly (everywhere) it was steam powered boilers running mechanicals, just like locomotive engines before electric-diesel locomotives were deployed. Primary fuel was coal, next most prevalent was fuel oil (aka bunker oil) which today is made from the absolute dregs of the oil production/refining cycle, Electricity was used for some things, but it was a small percentage of a "typical" factories energy budget, and a lot of the electricity was powered by...wait for it....steam boilers run heated by coal.
 
So oil is no longer used in production? Building planes will just need rubber and aluminium?

Any oil used as lubricant and the like probably wouldn't be enough to consider for manufacturing. An entire aircraft only uses a handful of metal, so imagine how small the oil requirements would be?

Im a little confused, if oil is no longer used in production, what is the meaning of excess oil? Wont all oil now be considered "excess"?? Can someone help me understand o_Oo_O

It'd be nice if we could trade resources that were considered ours (ie not on the market) but that we weren't using. I'd like that almost as much as I would the ability to buy our own resources off the market by adding extra factories to consumer goods (thus allowing the US to stay free market while also not gimping itself). But as far as we can tell, extra oil is just wasted.
 
Will there be an option to improve the amount of fuel a unit can carry? For example: a new support company that ads fuel trucks to your division. This way you could fight a bit longer if you get encircled or if you are fighting in a bad supplied region
 
Will there be an option to improve the amount of fuel a unit can carry? For example: a new support company that ads fuel trucks to your division. This way you could fight a bit longer if you get encircled or if you are fighting in a bad supplied region
I think that's what the logistics support does now, by reducing the amount of fuel the division consumes.
 
Looks great but the doubting thomas in me has a nagging feeling the AI is going to struggle somewhat with this, particularly as Germany, unless somehow it can utliise the resources from puppets and allies in a more efficient way. Hopefully the long term testing that you guys have put into this has helped.
 
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.

The UK should become especially vulnerable to having it's oil supply cut off now, IF subs are viable. And the US is going to have CIC to burn from trade.

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.

Let the debate on strat bombers being allowed in MP begin. If Germany is allowed to build unlimited synths and fuel capacity without fear of bombers, and doesn't have to worry about researching AA techs, building Positional AA, and building heavy fighters she is going to be a monster. Motorized Art is going to change template a lot. Also affects the meta on going Concentrated vs Dispersed.

Is Russia still going to be able to go to War Economy in 1936? If economic laws control stockpile limits, Russia could be sitting on a sea of fuel by 1940.

No more building 10,000 aircraft and 10,000 tanks without a care. Unless you build one hell of a fuel stockpile they won't be able to move. And building up your capacity burns factory slots. I like it. Got to put some thought into what your production plan will be years in advance.
 
The support company reduces the fuel consumption by 5% witch isn't a lot in my opinion

5% base, but logistics companies upgrade tech will probably improve that to be quite a strong bonus insofar as encirclements are concerned.
 
The support company reduces the fuel consumption by 5% witch isn't a lot in my opinion

Each tech level reduces consumption. So if each level is -5%, the total at level 4 would be a 20% reduction.
 
@podcat :
why not refineries building? i dont understand... really i dont understand... You can use as a pool like using factories but withj an own pool.

Pleace developers, this point is the easy part of oil, manage ai, proprity thats hard, but adding a building as refinery, build a pool of refineries is the easy part of this...

Or at least add refineries as a buiding that bust fuel production and reduce the efect when is bombed/damaged.
Taking refineries is a huge huge victory target from versalles to this days.
 
Any reason why fuel silos take up factory spaces? Why shouldn't they work similar to bases/defenses. Maybe each additional level of silo is locked behind a fuel capacity research.