Bully Dog premium ceramic coated exhaust manifolds are guaranteed to provide .3 to .4 MPG improvements and at least 30 extra horsepower. This is hands down the best exhaust manifold offered in the market today and it won't void your warranty. It has been third party tested to prove that it flows better than the stock manifold and the competition. The whole manifold is finished with a high performance ceramic coating which improves air flow and lowers temps radiating off of the manifold by 300 degrees.