Had 170 thousand miles on my Sienna. After reading all the great reviews about this product and decided to try it. follow all directions, put in intake, fuel tank and engine. Car started to leaking oil after 1 week putting sea foam in engine. after 2 weeks,leak gets worst, so changed oil and put Lucas stop leak in. No luck, still leaks as of today. Sea foam kills seals people, don't put it in your old car engine.