You'll find that your motor runs quieter and cleaner. If you notice a slight drop in performance, you can advance your timing by 2*. B99 is the way to go! Once you try the best to hell with the rest, which is why most of us drive Mercedes Benz! Oh, keep an eye on those little hoses that collect the overflow from the injectors and return it to the pump. Get some cloth covered fuel line and keep it with you. These will need to be replaced periodically.