Can you show your circuit? the number for both low and high dont make much sense.

 

@kubeek I turned the transistor 180 degrees, which fixed my problem. High side was connected to the collector. Brain fart.

For good measure. All the resistors is just me measuring stuff. It turns out, that the further away I move from the 1k resistor, the bigger the Uce gets. Is a low Uec an indicator on the right base resistor being used?

Uec = 0,071 V @ 1k res
Uec = 0,111 V @ 4,7k res
Uec = 5,10 V @ 100k res

 

To get lowest Uce, the general rule of thumb is that the base current should be about 1/10th of the max collector current expected. You maybe able to go lower with the base current to save some wasted power, but it should work in all situations as a starting point, or set and forget if you don´t care about efficiency.