Weird coincidence happened on my way home from the Pocono Raceway yesterday. It's a 65 mile trip. As soon as I left the track I smelled burning oil. I pulled over, yanked the engine cover and took a look around. No obvious leaks or smoke. Didn't think much of it. I smelled it the whole ride home and *thought* I saw a smokescreen behind me. I checked the mirrors to see if smoke was coming out the tail pipes. Nope. It was overcast and foggy in spots so I didn't think much of that either. Drove the 65 miles pretty much non stop. When I stopped to back it into my driveway there was smoke POURING out from underneath it. Funny I couldn't see it at stoplights, but as soon as I started backing up I could see it billowing out the front. I could see the trail of oil down the street and up the driveway. I was sure I had ran the thing out of oil driving it that far with such a huge leak.
But it was only down half a quart! Maybe it was getting worse and worse during the ride? Dunno. But whatever happened to the OP is definitely odd to lose that much that fast.
There's so much oil everywhere on mine that I can't see where it's coming from. It's over by the filter - a cooler line, sensor, or adapter. I'll have to wipe it down, start it up and see where it comes out.