15W 40 CI4 is a premium quality multigrade engine oil which provides outstanding performance in all petrol engine passenger cars.Flows faster in extreme cold temperatures where oil travels quickly to lubricate various engine parts. During hot temperatures, It has a lower tendency to Evaporate. Z Premium is more than just a stop-leak company. We are a team of enthusiasts and experts who create memorable experiences with each and every one of our customers. With nearly since 1975 of experience in helping everyday automobile owners repair leaks, we have the track record of success and long history that demonstrates our commitment and passion to helping drivers of all experience levels. YouÕll see that our passion shines through in everything we do.