Oil is the lifeblood of an engine, and in a hardworking diesel engine like the 1989-2002 Dodge RAM 5.9L Cummins, keeping that oil cool is essential to the engine's health. ---- A clogged or leaking oil cooler can reduce the oil's ability to transfer heat to the coolant, causing thinning and a loss of protection for critical engine components. Mishimoto proudly offers a stock-style replacement direct-fit oil cooler. This replacement cooler, complete with new seals, will restore and improve your engine's oil cooling capabilities and protect it from unnecessary wear. Like all Mishimoto products, this oil cooler is backed by our Mishimoto Lifetime Warranty for a lifetime of worry-free driving