The Stovebolt Site Forums The Shop Area General Truck Talk Oil weight inMissouri

I took the suggestion by Yar and called the Shell Oil Lubrication Engineer and he cleared up the question of which motor oil is best in older engines. He said that older engines need Zinc and he suggested to use Rotella T4 15W-40 diesel motor oil as it contains 150% more zinc than motor oil for gasoline engines.