Lately, I find that: Whenever the 2 charts are overlapped. we see that at a crossing of the bars there is huge movement in oil.
When USOIL is above, crossing the EURUSD downwards, expect a huge shift to continue in the downward direction. The same goes for when the oil price crosses EURUSD. Then expect a upward thrust.
In reality, It relates to the strength(or weakness) of the Dollar.