If you build all the tiers....
Sov:
15 + 20 + 85 + 90 + 80 = 290 fuel for the first T-34/76
Ost:
15 + 40 + 20 + 35 + 75 + 125 = 310 fuel for PzIV
OKW:
15 + 25 + 15 +60 + 15 +120 + 15+ 150 = 415 Fuel for PzIV
Get rekt son.
Someone forgot to add some fuel from M5 car from T3, cos you often need replacer on frontline and maybe 75-150 fuel for SU-76 for to keep enemy vechiles, cos you know what - USSR doesn't have panzerschrecks for those purpouses. So, while Ostheers and OKW can keep fuel for their tanks just spending ammo on shrecks, I have to spend fuel on tanks, cos I don't have any other effective AT. Specially, if I started with T1, not T2.