More importantly, you checked the oil before you left and it was fine. 300 miles later its what 3-4 quarts low, maybe more??? Thats a huge amount to lose you would see a leak like that.

Did the low oil light come on? Did the oil pressure drop? Was the top end going nuts? I would imagin if you ran the oil on a 603 that low the lifters would sound like they were going to come threw the hood!

Is the oil pressure reading normal now?

So where could the oil have went? Check the crank case breather and turbo.

__________________
2006 CL500
2009 C300 4matic
1969 280SE
2023 Ram 1500
2007 Tiara 3200