Density comparison using a Cessna 172 in MS flight sim

In this video I compare how air density is affected by temperature, pressure and altitude. I use a Cessna 152 taking off from the highest airport in the world Daocheng in China (14,500ft) 60 degrees c, 948 mb and then Newcastle at (250ft) 15 degrees c, 1013mb. Watch how the airspeed and climb rate is affected. There should be much less drag at the high altitude airport but the airspeed and acceleration is much less, see if you can work out why?