One more thing, without the thermostat it will always takes longer and longer to reach the optimal temperature (half mark). I don't know after how much time lapse you see the gauge for the needle to be at the half mark. But if speaking about my car, from a dead cold start even after 12 km in the morning when I would reach office, needle would still be on the 30-40% mark (fan off and no thermo). However if there were two or three signals in between the car would reach half mark comparatively quicker and I would have to turn the fan ON...so in that case the engine is still dying slowly...
i bought a qabli thermostat for khyber, costed 300 rupees from Magazine Line. Suzuki dealer was selling new one for 1400 rupees...lol. Anyways get your self a thermostat asap and you will get more life out of your engine.
Also when buying qabli, first check the thermostat that would be for your car. For example there are two heat ranges in khyber that I saw.. 88C and 82C and I found out that the one that I need is 88C and before buying the qablii I saw 88C embossed on it.
You can even buy a 100 rupee worth thermometer graded up till 100C and check the temp that the thermostat starts to open.