OK, I know what I have to do... But I wonder what the affects are... So here is what happened:
BMW Genius Marketing Team decided not to use a distinctive quart bottle for gear oil (vs engine oil). Yeah, the wording is different, but the picture of the rider is even the same!!
Any way, after the oil change, my buddy was opening and handing me quart bottles off the shelf as I dumped them in. I had one bottle of gear oil, and sure enough, it went in.
So, I have 3 quarts of 20w50 and 1 quart of 80w90 Hypoid Gear oil.
I know the correct answer is drain it all and refill, but what are the affects of running it in this configuration? Also, when I dump this oil, should I also change the filter? Or just dump it best I can and reuse it?
After you're done chuckling, I would like to hear your opinions.