It looks like black ink and it goes everywhere. Ran it in a hemi MP car for three years and the motor was great. It was also like tar, that wound up everywhere and could push itself through everything. That why it lost in the consumer market. A worn gasket or seal and it be there. I was surprised to see that it is still being manufactured. All the bearing surfaces where coated with STP and the black oil was used as break in w/o any problems.