Phillips 66® Ramar Diesel XDO is a high-quality, zinc-free, heavy-duty diesel engine oil designed for use in all 2-stroke cycle and 4-stroke cycle railroad locomotive diesel engines. It also is recommended for use in railroad-type diesel engines used in marine service or in stationary service for power generation. It is formulated with a new technology, reduced ash (11 TBN) additive package that is particularly recommended for use in modern Progressive Rail and GE power units running on low or ultra-low sulfur diesel fuel.