STP® Engine Stop Leak is formulated with a special agent to renew polymer seals and gaskets damaged by the heat of normal engine operation, which can otherwise result in oil leaks and expensive mechanical work. STP® Engine Stop Leak will also increase the protection offered by the existing engine oil.

The entire contents should be added to 4-5 litres of engine oil (approximately 15% treat rate), and leave the engine to run for 15 minutes. At the normal oil change interval drain as usual. If any leaks persist beyond 1,000 miles/1,500km, mechanical repairs may be required – consult a trained mechanic.