Mechanic In A Bottle Diesel Fuel Treatment is a product specifically designed to improve the performance of diesel engines. This fuel additive is formulated to help maintain the fuel system and reduce engine wear and tear. It is a convenient solution for diesel owners looking to optimize their vehicle's fuel efficiency and keep their engine running smoothly. Helps reduce frequent regens and DEF usage. With Mechanic In A Bottle, users can enjoy better engine performance and reduced maintenance costs. You will receive (1) 24oz bottle of treatment. Free shipping.