Why don´t these figures match up?

[NaBkin]

Hi folks,

I´ve been doing some tests for navigation. Basically I wanted to figure out the time I have to fly for a certain distance.

So I did this test in QMB (no wind, 100 meters hight):

Time: 3 minutes (0.05h)
Speed: 250 Km/h IAS (with this low alt and speed TAS/IAS shouldn´t make a big difference I guess)

So after the math is done (250km/h x 0.05h) the flown distance should be exactely 12.5 Km

I did the test several times with several planes and everytime the actual flown distance is 14,5 Km (that indicates a speed of somewhere around 285 Km/h).

Does anyone know where I did the mistake or is just some of the tools in the game broken (Speed gauge or distance meassure on the map)?

Thanks for help!