A semi-synthetic 20W-50 version of our original formula, XP5 offers excellent bearing oil film thickness and high levels of Zinc with out the extra cost of a full synthetic. Appropriate for both Gasoline and Alcohol fueled engines. XP5 is designed for looser clearances and aluminum blocks. XP5 works well in Dirt Late Model engines and other engines designed for SAE 50 weight oils. XP5 performs the best in engines operating with oil temperatures between 220F and 260F