Yellow shell engine oils include HX5 and HX5 Plus, in which HX5 is mineral oil with viscosity grade 5W30；; HX5 Plus is a semi-synthetic oil and an upgraded version of HX5. Overall, it is better than HX5, including 10W40 and 5W30 viscosity grades.

Shell Heineken HX5 is a mineral engine oil that pays attention to cleaning performance. Compared with ordinary mineral oil, it not only has unparalleled wear protection performance, but also has long-term stable oxidation characteristics, which can improve the engine protection ability by up to 30%, thus effectively prolonging the service life of the engine.

Secondly, the selection of synthetic base oil is very helpful to the performance of engine oil and the fuel economy (emission reduction) of automobiles.