Dura Lube® 32oz Engine Treatment: Dura Lube is an advanced liquid formula precision blended to reduce friction and heat when added to any vehicle engine; gas or diesel. Dura Lube works with any lubricant including synthetics. It contains no solids to clog filters or reduce performance. Directions: Replace 1 quart of engine oil with 1 quart of Dura Lube Engine treatment, use every oil change, or top off any time between oil changes. Will not void manufacturer warranties