Someone just read my mind! I gonna immidiatly test all this stuff with my hardcore modpack (basicly its rampant+explosive biters and a lot of little supporting mods + tweaked settings of vanilla game which took me more than 40 hours to balance parameters of all this stuff. I hope this mod will fit very well.

I am glad that you find this mod interesting.
Be sure to tell me what you think after testing, hope you will enjoy it.

Interesting enough, fully equiped(20shields MK2 + nuclear reactor) super heavy tank still not OP against Titans which provided by "explosive biters" mod, even with 0.5 hp and dmg multipliers which i use (default 1.0 is toooo much).

Light tank is great, it removes stagnation in weaponary, some sort of fresh stream, better car. But medium and heavy meh... i think they can be merged into one, cause difference between "medium" - "heavy" - "super heavy" is too smooth.

Also i think give to player all types of tanks after open single tech is too much, tank technology research can be rushed in couple hours, so even increaced cost of them is not good restriction to prevent using super heavy tank in early game, u know, even in my hardcore military mod pack i usually build 100-200 furnaces(cant keep up more, cause you forced to fight with biters so much and they not allow you to build "mega" base) For vanilla it can be x2 x3 or even x10. Steel? Engines? Peoples have chests upon chests upon chests of this stuff. So i recommend to split all tiers of tanks in to separate technologies, with Hi-tech packs for super-heavy one. And also recommend to add more "complex" ingredients in to craft recipie (like you did in MK1-2 upgrade) quantity does not mean quality. 50 steel or 500? Who cares?

Another problem is super-heavy tank + Nuclear fuel which gives 250% acceleration but for some reason also increase top speed up to 45+ km/h and at this point its not feel "super heavy" Maybe it worth to dramaticaly decrease base speed of super heavy tank to make it almost immobile without at least rocket fuel (20-25km/h with uranium fuel maximum). It can be additional "good" reason to NOT use heavy tanks in early game with solid fuel or even coal

Suggestion to make more variations and differentiation in tanks: at this point you made awesome early game light tank with auto-cannon, maybe you can go deeper and rework super heavy tank.
How i see this mod in my dreams: 3 tiers of tanks + Flame tank+Rocket artillery (btw its really good for launching nukes, you been right). Light - autocannon, Medium - almost like vanilla, like you did it right now, Super heavy (skip heavy to more difference between tiers) with absolutly new, hi-tech laser cannon, which have piercing mechanic like rail gun (present by vanilla game, can be spawned in map editor, but for some reason not implemented in to gameplay) which have infinite(it seems like) penetration and damage all units in line. Something like "AAI Vehicles: laser tank" modification. Just enormously large, heavy armored, futuristic tank with complete new laser gun. It has interesting concept "focuse ammunition" which instead of damage all units in line, deal increaced damage to primary target and dont have collision. This mod btw have shitty balance, this laser tank in underpowered cause his damage is scaling up with upgrades(still a little bit low), but RoF is not, so in late game it has even less DPS than vanilla tank. also focuse ammunition bonus dmg is to small(must be dramaticaly increased) so it worth only cause it doesn't damage friendly structures. But you can have a lot of inspirations from this mod.

One more little wish - make flame tank gun mechanic similar to player flamethrower (arc, creates fire puddles, not "aerosol" stream)

aaaand another one(in addition to "one more little wish"), instead of adding fire tank, you can add flamethrower for car.
Don't create a large number of entities, it is better to specialize the existing ones. (i think even better to hide vanilla car like you did with tank then add new car, with machinegun and flamethrower)

about rework, i think its better to embed MK1 - MK2 upgrades in to Medium and Super heavy tank. The bigger tank you have - the bigger module grid (otherwise light tank can become enormously tough to kill cause it share same module grid size as higher brothers. This also means merge their recipies(speed, efficiency modules, electric engines) with tank recipies.

It would be great if you make additional techologies required for research next tiers of tanks, for example ofc you cannot craft SH tank without efficiency module 3, but it will have much more sence if its technology will require "efficiency module 3 technology" to unlock. Same for flamethrower tank? Yes you can create it, but for some reason it doesnt require "flammables" or "flamethrower" so you not even able to create flamethrower ammo! whats the point?

Thank you for your detailed feedback. This give me some planned changes already in my mind.

Firstly, this mod is intended not to change the basis of the vanilla game too much, not adding OP stuff to the game. So a fully-geared super-heavy tank MK2 is actually "desired".
For a REAL EXTENSION for post-space-science combat, or OP gears versus other OP enemies, I am having another mod still in development, featuring some MK3 (maybe MK4 too) tanks which have big upgrade in firepower (currently base and MK2 firing the same guns), and some bullet-firing vehicle equipment, even larger game (like some Power Armor MK3 mods), etc. I am also experimenting with some ideas, which also affects mid-game. Feeling you are enjoying heavily-modded combat. So I guess you will need this WIP mod instead, in order to fight those "explosive biters". :D

Light tank is the most-creative (the "most-deviated" unit from the vanilla game), since the only newly-created ammo type "autocannon shell" is dedicated for it. I am glad that you like it.
Medium tank is identical to vanilla tank, just taking off flamethrower but having equipment grid. This serves as a identical replacement of vanilla tank, so new changes won't be made to it.
Your comment on "medium" - "heavy" - "super heavy" being too smooth is right, players are getting heavy and super-tanks too easily. In real history, heavy tanks took a lot of effort and time to develop, and appeared quite late. It was even more true for super-heavy tanks, most of them not ever completed. Like what you said, I should add new (expensive) technologies to unlock them, together with more scarce resources to manufacture them.
Yup, super-heavy tank is too fast, especially as when nuclear-fueled it can outrun biters even without exoskeletons. It needs a nerf. This may make the whole tank series more distinguishable in their roles.
To make them more different, another idea is to have cannons of different caliber (like medium: 75mm, heavy: 88mm, super-heavy 128mm). Currently the three tanks share the same cannon shells, so I cannot do much changes. But with different caliber guns, it is more justified to differentiate the performance and in a historically-realistic sense. High caliber guns have more range, more AP power, larger HE warhead, but much lower RoF. This idea was not implemented, because the new caliber guns need to use different ammo type. I worry this may make the ammo logistics overcomplicated. But since all the changes made (like the above-mentioned new tech), it maybe necessary to bring these out.
This maybe a good substitute for your hi-tech guns idea. The caliber guns choices are both historical-accurate and logical to do so. Plus I try to avoid altering the "feel" from the vanilla game too much.
However, your idea on hi-tech laser cannon, rail gun is great! If you don't mind, I want to apply these to my WIP mod tanks instead. :D

Changing the tank flamethrower is easy. I will provide an option to change that, just like what I did on personal laser defense ammo category option and discharge defense auto-trigger option. I will make a quick update on it today or tomorrow.

I am thinking of the car, but giving it a flamethrower may make it redundant to the flame tank?

Light tanks MK2 (with 15 Vehicle Shield MK2) is still easy to kill, 3 shots of uranium explosive cannon shell from super-heavy is enough to kill it. And for PvE, a behemoth biter group intercepting you can still kill you easily. So I guess it is "weak enough"?

I avoided to create additional technologies to make it more "fit" to vanilla game. But since it is unavoidable with the coming changes about heavy and SH tanks, it will be done, and to flame tanks too.

It may take some time to do the changes, so please be patient! :D

Yeah i balance my modpack around vanilla too. Its not change original content. I feel like I have to tell a little about it.
Add new AI - Rampant
Couple new enemies - explosive biters (gives to biters much more opportunities to break the player’s defense), Worm attack (yeah, they dig straight to your base in late game)
And additional tools to compete with all of this:

long range turret(expensive, more durable, 28 range, more dmg but same dps, slower turning)I'm still not sure about the need for this turret, its kinda interfere with another long range "cannon turret"

Cannon turret(great long range, armor piercing, high physical damage tool, 12blocks dead zone, so it must be protected from melee, it uses vanilla cannon shells but in magazine form)

Scanning radar(scout)

Mustard artillery shells (great anti worm cause they dont have resists to poison)

Turret shields - allow player to survive until repair drones researched

Deep core mining - late game infinite resourse source, cause it seems impossible to create outposts

I play with MAX evolution time factor, this means after 3 hours evolution reach 0.5 = T3 biters with 375 hp and 8 physical armour , after 24 hours first behemots will appear (0.9 evolution factor)

So it some sort of Speed Run but in military and defence instead of rocket silo. My record by far is 6 hours(and only first 4 science packs produced) in coop with another player - yeah its very very tough task to survive here (map generation = water only on spawn, which means you must create full 4 wall perimeter and not able to sit and defend couple choke points)

So whats wrong with vanilla tanks? it has no late game variations, developers instead of adding new vechicles just add crazy upgrades for existing tank. His base RoF = 0.67, but fully upgraded it has 0.67+1.53=2.2shots per second, a little bit too MUCH for tank cannon! Especially for this steampunk looking tankette.
For example turrets from "cannon turret" mod have only 0.33 base and 0.33+0.77 fully upgraded RoF and it feels and sounds much "tank like"

What is really nessesary - first of all remove "Cannon shell shooting speed" upgrade from game, because its become really hard to balance vechicles, in the beginning they may seems fine, but did you know fully graded Light tank have 6.67+15.33=22 shots per second and 30+96 explosion dmg inside 4 AoE, it destroys Behemot formations in less than 3 seconds. it's just a crutch to replace the further progression of vechicles with upgrades which

Autocannon - looks like it has 0.1 dmg, and X10 RoF = same dps but smoothed in time, without peaks (like cannot shot)
Explosive autocannon shells must be nerfed in dmg to fit at least vanilla behemot biters, their parameters is 3000hp 12/10% physical and explosion armour. Dmg = (initial damage-12)0.9 https://wiki.factorio.com/Damage#Resistance
I think good number is 15(for explosion AoE) - So the higher tier of enemy, the less efficient autocannon become and reqire damage upgrades to keep up with tougher enemies. FInal dps against behemots (((153.2)-12)0.9)6.67 = 216 (I HOPE MY MATH IS CORRECT, anyway double check this pls). So it will be fine against T1-T3 biters and kill them relatively quick, but for behemots you better get stronger tank or at least have high damage upgrades. Anyway it hit groups of enemies, not single target.

In this balancing things you must calculate at least 3 damage tiers.
1) default dmg, do it fit very vell at the point where you get this weapon?
2) dmg with first 4 packs upgrade = +70% for cannon shells (default1.7), because its pretty cheap and can be researched relatively easily
3) full grade dmg, which require hi-tech science packs(pain in ass) = +220% (default3.2)
all these 3 damage numbers must be calculated and also multiplied by RoF.
As you can already see, its better to remove "cannon shooting speed" upgrade, cause already there is a lot of balancing math, and if we have different levels of RoF things become overcomplicated. (its good to add possibility to disable endless upgrades in mod settings too)

Another good example is leviathan worms added by "worm attack" mode, they have interesting armor against lasers, 50/60%. 50 flat armor looks just like random number? But hell no, did you know 20+30dmg is what exactly laser turrets have with "cheap" damage upgrades (first 4 packs, without Hi-Tech). So to be able to pierce his armor, you must research further upgrades! This is how balancing must be done, not random damage numbers or resists, all must be precalculated

After this wall of words i have a little bit more, suggestions for tanks:

Light Tank - early game fast tankette for hit and run, mostly effective against T1, T2 biters, have decent effectivness against T3 (they have 8 flat armor against physical, but 0 against explosion, high health pool their only advantage), but must be replaced or atleast strongly upgraded to be compete against behemots (maybe even less than 15(12) explosion dmg, without testing I can not say more precisely). No vechicle grid by default, but small after upgrade (5x4)

Medium tank - vanilla tank, same parameters as you did already, probably if you remove cannon shooting speed it will be already balanced. Use default vanilla ammunition. Small vechicle grid by default (5x4), medium after upgrade (7x7)

Heavy tank and Super heavy, i see you really want to keep this two separate, but there is not only cost is smooth, but their parameters, 2500hp or 3000hp, slightly more resistance and thats all? Difference between cannons also not so dramatic. So if you wanna keep heavy, maybe there is a good reason to implement new cannon with greater caliber and new, more powerfull ammo for this. But dont forget to balance stats, especially rate of fire, because instead of have same DPS as Medium tank, it might have even less! but compensated by alpha strike, to beat high flat armor targets, it will emphasize his role as alpha strike anti high tier enemies/tanks (this means you must rebalance resistances of your own machines. For example: to create situation, where autocannons will just scratch armour of heavy and super heavy tanks, even fully upgraded - Maximum upgraded autocannon explosion and physical dmg must be fully absorbed by flat armor of at least SH tank) Another good idea is for secondary weapon slot add autocannon instead of twin machinegun. Grid size 7x7 by default, 10x10 after upgrade.

Super heavy tank, my favorite part, as i already said i would cool if you create, complete new, raingun based tank, which damage type is "laser" and will scale from laser damage upgrades. I can give you some initial numbers from AAI Vechicle mod, but my personal opinion - they must be buffed. Btw laser, is the only weakness of Titans, they have 0 flat armour, and smallest resistance in their palette = 50%. For you it also can fit well, cause you can make other tanks vulnerable just by set their laser resistances is low or even none for LT and MT, which means this rail gun will cut them like hot knife through butter. Grid size 10x10 by default, no upgrades.

What about fire tank? It shares same hit and run playstyle with LT, so i again see good opportunity to merge them in to one, add flamethrower to LT and remove existing firetank But see for yourself if you want to produce more entities then it is your right.

From your description, I can imagine it's a very hardcore enemy mod. But since it's not vanilla, it would be difficult for me to imagine or consider the situation. So for the time and effort concern, I am sorry that balances can only be based on the vanilla game.

First of all, I share many of your viewpoint on the vanilla game. Cannon shooting speed upgrade bonus is too high. Cannon firing like autocannon is unrealistic and off-balance. The same is for laser turret, long range shots, combined with free energy from solar panels and zero laser resistance of biters, it is the "mindless" defense option, making the gun turrets obsolete (even for insane gun turret damage upgrades). Only on death world like scenarios will find some uses of flame turrets, but still laser turrets form the major base defense.
Then it is the damage upgrades that makes things off-scale (thus hard to balance). Player damage upgrades boosts a lot, while evolution factor only make biters more numerous but not upgrade in their resistance. These combined make ALL player weapons to be OP versus biters, not just my autocannon. Only the short range prevents some weapons (like shotgun, and gun turret) from being useful.
The idea of autocannon shell is to "split" a cannon shell into smaller shells (so comes with 0.1× damage and 10× RoF to compensate the apparent DPS). The true DPS will actually be lower, since lower shot damage is affected by resistance. The autocannon also has shorter range too, so I felt there are already enough nerfs. Some nerf maybe needed, but I would want to hear feedback from other players first.

By then it comes to one big question, two options: should I stick to vanilla game and balance with it, or do a complete rebalance?
Yes, the latter option is very tempting to me. I want to make cannons more realistic. I want to make gun turrets more useful even in late-game. I want to make laser turrets not the "mindless" choice.
But for now, since this is my first major mod, I choose the former option. You can see I have not removed any vanilla entities at all. Even for changes (like vanilla tank recipe, personal laser defense ammo type and damage) I provide options to toggle off. This is a benefit to many players, who want to keep the "vanilla flavour", and treating this mod as a PURE ADDITION mod instead of changing anything they like.

Therefore, although I feel cannon shooting speed upgrades needs a nerf, I will not modify it in this mod (but in some future rebalance mod). Since autocannon is a descendant of the existing cannon, I am not changing its upgrade bonus neither. Sorry I cannot satisfy this demand without sacrificing my principle on this mod.

Your suggestions on tanks are quite different from my setup, I will need more time to think about that. But there are some points I can answer for now:
The idea of autocannon as secondary weapon to super-heavy tank is a "no". It would make the overwhelming super-heavy tank even more favourable, without the need of supporters to handle swarms of small biters. Even worse is taking away the role of light tank. My idea is lighter tanks deal with swarms and heavier tanks deal with tough ones. If super-heavy tank is good at both, then that's exactly your first feedback was worrying about: everyone just drive super-heavy tanks, without any diversity.

For tank flamethrower, I feel it is underpowered in vanilla with its short range. So I decided to boost it to "main gun grade" so extended its range from 9 to 15, and put to a dedicated flame tank. And this is why I decided not to put this buffed flamethrower to the medium tank.
But actually 9 is a realistic value considering its real-world range. So if it is added to light tank as secondary gun, it must return to the vanilla range of 9. Is it acceptable?

No, keep flamethrower inside specialised one tank then.

Sadly enough, vanilla doesn't provide tough enemies to player, so even vanilla tank is powerful enough to beat hords of behemoths, i thought you wanna rebalance whole vechicle situation in factorio and replace "stupid OP upgrades gradation" to "tank variation gradation" with completly different tank types, which have different primary targets/role. But if you stick to "Pure addition" concept, then players just don't need super-heavy or even heavy tank, they out of place, cause there is no good enemies what you cannot beat with existing tank. Maybe for PvP purposes only, but let be honest, almost noone play factorio as PvP game.

Vanilla biters very vulnerable, only T3 have decent armour against bullets (8 flat and 10%, base dmg of green ammo is 5, piercing is 8), so player must have done couple researches in to bullet damage and turret damage, cause in stock state they deal 1dmg and, ofc, player lost his defence very fast (remember, at max time factor first T3 appear after 3 hours and its pure vanilla). Further tier is T4 aka Behemots, they have 12 flat +10%, but enourmously large health pool. But after adding flamethrowers(freeammo, no energy drain OP turret) to defence, even behemots will fall, especially after couple fire damage upgrades.

What i did is just add enemies what have resistance to fire(explosion biters) and laser damage(worms), it makes all turrets important, you cannot just spam laserwall with couple flamethrowers. Also fire spitters doesn't allow player to place turrets in to neighboring cells, because they create fire puddle and it will damage 3 turrets instead of 1.

Just released a major revision, which includes:
- Adjustments in all cannon range, fire rate
- High caliber cannon shells are much more powerful (but also more expensive)
- Technologies to unlock different tanks
- More costly to both research & manufacture super-heavy tanks
- Adjustments in physical & explosion resistance for upgrades, to scale better with late-game damage upgrades.

Hope these satisfy some (if not most) of your requests.

Hey its me once again, this one is better but not quite enough, let me explain, just in case if we play factorio differently. Usually players create a fully automatic science pack assembling lines, with ratio of 5:6:12:5:7:7 (to get equal ammount of science packs per second) or even X2 of this ammount. So it means after they already reach first 4 packs (red green blue and military) they can research all technologies what require this packs pretty fast and again what i see is player just able to research "tanks" then"heavy tank" then "super-heavy tank" in couple minutes and get acces to all tiers. 200military science packs cost is nothing, you can run on your military SP output belt and just hold "F" (by default) key, to get enough. Maybe, just maybe, you produce science packs from 1 assembling machine (each type) and for you it requires pretty long time to unlock all technologies, but it isn't only way.

My suggestions:
For heavy tank, at least change 100 normal engines in recipie to 100 electric engines( I understand that this is not realistic, because you have a burner engines in your tanks, but we simply don’t have more suitable parts), this will require separate assembling line for crafting them to delay(and complicating) appearance of heavy tanks. And i highly recommend to add "Military 4" research in to requirements to unlock "heavy tank" research.

For super-heavy tank, same with engines, swap default ones to electic (at least here, cause MAUS have electric transmission, cause it's developed by Porsche). Instead of 200 military packs add at least fusion reactor to recipie (requires 250 processing units (blue circuits)) and probably couple productivity modules 3.

Add "portable fusion reactor", "military 4" and "artillery" researches in to requirements to unlock "super-heavy tank" research.

About artillery, look at the stats of artillery shell. 500physical, 500 explosion, 4 radius. Its has almost the same stats as your 128mm shells, add them to recipie of 128mm shells instead of multiplying steel, plastic and explosives requirements. Because this is stupid, you can use same assembling lines to create all 3 types of ammo, cause you already have all 3 resource input lines. Adding artillery shells will complicate this process once again. (think about some addition to the 88mm recipe too (granade?))

I know you already have fusion reactors, speed and efficiency modules in recipies of MK1 and MK2 versions, so i don't know what to do here. Maybe think about reworking this system of upgrades and add its stats by default. 1000 2000 3000 5000hp by default and configurable vechicle grids for each tank type(4default+rocket+flame) in mod settings instead of configurable vechicle grids for default+MK1+MK2 upgrades.

The suggestion of electric engines on super-heavy tank recipe has a very good point. The two prototypes of Maus were using different types of engine (petrol and diesel). I will apply it in the next balance update. (Probably not so soon but on weekend.)

In previous update I have reduced the speed of heavy and super-heavy tanks greatly. And in this update their tank cannons have much lower RoF. So they are no longer pure-good upgrade over medium tank, since they are not good against swarms. Maybe these nerfs were not enough, so I will lower the turret rotation and chassis rotation too to amplify the differences?

I have a feeling that we have quite different uses and opinions on the position of super-heavy tanks... I defined the basic super-heavy tank as a mid-late game item, which comes even later than the power armor (note the research cost). But to make good use of it, nuclear fuel is required to power up the so-slow moving tank.
Basic super-heavy tank costs 300 science packs of four types, while power armor only costs 200 science packs of three types (not even military science packs!). Only power armor MK2 is more costly than this (costs 400 science packs of five types). So I feel basic super-heavy tank has the right position in the tech-tree, in terms of usefulness of the basic super-heavy tank. The basic super-heavy tank is not that super-useful nor OP at that moment, due to the low speed. Plus, an addition 200 military science packs to craft EACH unit is actually quite costly at that point of the game.

Super-heavy tank MK2 costs 1200 science packs of six types, while nuclear power costs 1000 science packs of three types. I honestly do not think super-heavy tanks MK2 should be higher tech than nuclear power, but I made it more costly to research than nuclear power anyway. And I define super-heavy tank MK2 as a very late-game item BUT still lower tech than atomic rocket. Players spend much less time clearing nests with atomic rocket than super-heavy tank MK2, right?

While the situation you have mentioned (like fully automatic science pack assembling lines...) have all resources and items anyway... You probably can craft anything, leaving only atomic rockets being considered expensive. So I guess that is the reason why you feel the whole line of super-heavy tank research is easy to you.

Lastly is about the recipe of shells.
Factorio artillery has ZERO position error in targeting, despite the extreme long range. It is not achievable with pure ballistic shells, whereas such long range would also require enormous amount of initial speed (which is why rail guns are used for in real life). In my opinion, in-game artillery shells are more like satellite-guided or GPS-guided missiles (or whatever with very high precision control...), and has in-flight propulsion. Therefore, artillery shell has additional ingredients: explosives are for propulsion through the long range flight (kind of, although rocket fuel may fits better here), radar for terminal guidance so to acheive precision. So in my opinion, these extra ingredients are added for reason, instead of randomly complicating the recipe.
Cannon shell, is a totally different story. Honestly I feel cannon shells are quite low-tech item. Large caliber shells are merely kind of scale-up variants of their smaller caliber cousins, more or less the same design. They are designed to be mass-production products. They are designed to be simple and easy to make. So it is unfair to compare the mass-produced tank shell with the extreme high-tech artillery shells (missiles). Honestly I do not see any reasons why large caliber tank shells would need extra advanced materials to make. In addition, it is completely logically to use the same production line (with very minor adjustments) to produce similar armaments, like in real-world.

Did a quick update 0.16.3, reducing the turret rotation and chassis rotation speed of heavy and super-heavy tanks. Hope it's enough to make them not "good-in-everything" tanks.