You can claim the Head of Household filing status on your tax return if you pass the support test, the residency test for a qualifying person, and are unmarried at the end of the year. There are also special rules that relate to separated parents and married couples who live apart from each other.
Motor oil. Motorcraft also sells motor oil for automotive use. As of the late 2000s most of their oil is a synthetic blend or fully synthetic. Several weights are available from the 5W-20 all the way to a 15W-40 for diesel engines.
In USA most of the Motor Oil and Gear Oil that is labeled as synthetic is actually produced from API Group III Petroleum Base oil. Therefore the prices of such  synthetic  oils are also directly related to the current pricing of Crude Oil and the current Base Oil Prices.