Convert L/100K to MPG, or show more figures on the display.

I have a European Prius and the consumption is displayed in terms of L/100Km rather than MPG, is it possible to convert it to MPG? or at least show more significant figures on the display.

The reason I am asking for this, is that the resolution when displayed in MPG is 10 times better than when displayed in L/100Km.For example, the MPG range 49.6 to 50.6 translates to 4.7 L/100Km (it is in fact 4.65 to 4.74 but the computer rounds it).

Now, the significance in having a better resolution is telling the driver whether he is driving better or worse. In other words, you will see the consumption vary, rather than just seeing a 4.7 for over 50 miles then it is suddenly 4.8! or 4.6.

Viewing the last 15 min consumption seems to be a good workaround, but it is sometimes meaningless since it is in terms of time rather than distance.

So is there any other way around this?