ProTecta High Mileage Formula is especially engineered for vehicles with over 50,000 miles. Over time your vehicle accumulates deposits that build up and form sludge. Such material accelerates the wear in your engine when moving parts rub against such deposits. The detergents in ProTecta High Mileage release such contaminants so that they can be removed by your oil filter. In addition, a vehicle that has over 50,000 miles is usually a few years old and the seals in your engine become brittle, hard, and shrink, which can cause oil leakage. ProTecta High Mileage conditions and softens seals to their new condition to prevent oil leakage. Use an entire bottle at least every 6000 miles to keep your engine clean and performing to its optimum capacity.