Small size hasn't translated to less internal fuel...
Internal fuel capacity:
HAL Tejas 2,458 kg
JF-17 2,350 kg
Weapons load is very comparable ...
Carrying capacity:
3,500 kg external fuel and ordnance (8 hardpoints, of which 3 wet)
3,629 kg external fuel and ordnance (7 hardpoints, of which 3 wet)
Which means, IMHO, that combat radius is dependant on specific fuel consumption of the respective engines for a given flight profile and external load (= fueltanks, weapons, sensors).
F404-GE-402
- Military thrust: 82.6 kg/(kN·h) (0.81 lb/(lbf·h))
- Full afterburner: 177.5 kg/(kN·h) (1.74 lb/(lbf·h))
Klimov RD-33
- Specific fuel consumption:
- Military thrust: 75 kg/(kN·h) (0.77 lb/(lbf·h)) dry,
- Full afterburner 188 kg/(kN·h) (1.85 lb/(lbf·h))
WS-13 ?
See also http://www.globalsecurity.org/military/world/china/fc-1.htm