New block: 1x1x1 fuel tank - capacity e.g. 200L - very vulnerable, extremally explosive (One arrow can kill you if fuel tank is not armored - the knights will be glad ))

Starting block = default free fuel tank: 50L

Simply add fuel usage to blocks e.g.:
MOTOR WHEEL- 1.00x setting - consume 1L of fuel per second (at 2.00x = 2 Litres)
   (20 wheels monster with one tank 50L+200L = 12,5 seconds of movement.)
FLAME THROWER -  10 L/s
FLYING BLOCK - 1 L/s
STEERING, DECOUPLER, SPRINGS etc 0.1 L/s
PISTON - 1 L/s

In menu: Ability to disable the fuel system. (e.g. Free build mode)

Effects:
- Strategic matching the size of the tanks

- Balancing between the range and firepower

- Additional cost for armor of the fuel tanks
- More stupid accidents