In that case there's really a very small delta (based on official GWM numbers so take it with a grain of salt) between the H6 HEV and H6 PHEV.
I was actually able to look up the official figures after @mgalaxy3 brought up the concern regarding the efficiency loss due to the larger battery. Here's what GWM claims officially:
H6 HEV FWD (NEDC): 19.23 km/L (5.2 L/100 km)
H6 PHEV AWD (NEDC, fully charged): 90.9 km/L (1.1 L/100 km)
H6 PHEV AWD (NEDC, low battery): 18.86 km/L (5.3 K/100 km)
According to these figures, the H6 PHEV does loose on efficiency after it's completely depleted, but the drop is minuscule (5.2 L/100 km vs 5.3 L/100 km).
Based on these numbers, I had ran a simulation of a highway cruise distance of ~370 km at 120 km/h. This is the typical distance between Lahore and Islamabad on M-2. To keep things simple, I just assumed that both cars would be cruising at a locked 120 km/h speed without any variation. They also start by having full fuel and battery.
Even based on this scenario, the H6 PHEV ends up being more efficient even if it only does 60 km on pure EV. It would require around 16.4 L of fuel vs. 19.23 L of fuel required by the H6 HEV.
Regardless of the scenario, the PHEV ends up being more efficient and cheaper in terms of fuel as long as total distance travelled without recharging is under 3,000 km. Factoring in a price of around PKR 42 / kWh of charging at home, it would still be more cost effective around a distance of 1300-1400 km total without recharging.
Obviously these are all assumptions based on quoted figures and hypothetical scenarios.