John Walker tanks an oil truck explosion.
M = e/E*m
M = TNT Equivalent Mass (kg)
e = Specific Detonation Energy of Explosive (J/kg)
E = Specific Detonation Energy of TNT (4 600 000 J/kg)
m = Mass of explosive (kg)
Specific detonation energy of crude oil is 41 868 000 J/kg.
The truck in the feat look similar to the FAW Tanker Truck which has a tank volume between 396 and 792 gallons. Low-end of 396 gallons, or 1.49902 m^3.
Oil has a density of at least 870 kg/m^3.
1.49902*870 = 1304.1474 kg or 1.3041474 tons
41868000/4600000*1.3041474 = 11.8700094224 tons, City Block level
However this is for a 11.15 tall truck. The truck in the feat seems to be shorter.
John Walker's leg: 110 px or 0.79 m
Truck height: 251 px or 1.80 m
(1.80/3.39852)^3*11.8700094224 = 1.76359593388 tons, Building level+
Tire height: 23 px or 114.3 cm
Explosion diameter: 249 px
Explosion radius: 124.5 px or 6.18 m
Assuming a sphere, the volume of the fire would be
4/3*pi*6.18^3 = 988.676097287 m^3
Jasonsith says this looks like deflagration, so I'll use this method.
Oxygen density is 1.3311 kg/m^3.
988.676097287*1.3311 = 1316.0267531 kg
Oxygen is 13062500 J/kg
13062500*1316.0267531 = 1.71905994624e10 Joules, 4.10865187916 tons, Large Building level
Eh, might be an outlier, but I still want to check if the math is correct.
Recalc by Jasonsith
114.3 cm is actually the diameter of the rim.
Recalc by Jasonsith
249 px / 2 = 3.09355 m
Then volume = 4/3 * pi * (3.09355 m)^3 = 124.0114712 m^3
Oxygen mass = 124.0114712 m^3 * 1.3311 = 165.0716693 kg
Deflagration yield = 165.0716693 kg * 13062500 J/kg = 2156248680 J = 0.515355803 ton TNT (Building)