Hi Commanders! Can someone please help me in understanding how I'm meant to be reading the jump range of my ship? I feel like a total amateur even though I've been playing since the Beta and thought I had a good grasp of Elite's mechanics. I've fitted a class A5 Frame Shift Drive on my lovely Diamondback Explorer. In the fittings page in the stats info in the bottom right it tells me at the very least, I should be able to jump 29.10 ly with it. Everything is fully powered on my ship. My cargohold is completely empty.
So why does this show that the furthest I can jump is 19.1 ly?
Am I interpreting the raw numbers wrong from the outfittings screen? Or something else? Thanks in advance.

So why does this show that the furthest I can jump is 19.1 ly?

Am I interpreting the raw numbers wrong from the outfittings screen? Or something else? Thanks in advance.