NEW from Lucas Oil Products, Our Engine Oil Stop Leak is a unique formulation of Lucas additives and very specific base stock designed to stop seal leakes in engines. It contains nothing that could be harmful to an engine and can actually extend the life of engine oil by at least 50%. In petrol engines: A puff of white smoke out the exhaust in the morning is a sure sign of worn valve seals allowing oil to seep past the valves into the combustion chamber when the engine is not running. This is a sign of a high mileage engine, allow a few days for Lucas Engine Oil Stop Leak to correct this problem. To keep the problem correct a quart (litre) will be advised to be added with each oil change. Leaking engines are usually older engines. Lucas Engine Oil Stop Leak is not only a leak stopper but also an excellent additive for worn engines. The user can expect less engine noise, higher oil pressure and less oil consumption as the Lucas additives fill the space between worn parts. Lucas Engine Oil Stop Leak is also effective at stopping leaks in automatic transmissions, hydrostat transmissions or hydraulic systems. 10% is usually adequate - more can be used in badly worn units. Directions: In automobiles replace a quart (litre) of engine oil with a quart (litre) of Lucas Engine Oil Stop Leak. In larger engines, usually diesel, use 10 to 20%