I was at the auto-parts store yesterday and the guy was looking at my New 2015 F350 and he was telling me I should start using a fuel additive while it is new. He said it will help keep the engine like new and perform better. He recommended "Lucas Oil" diesel fuel additive. I talked to my neighbor who is a Cummins mechanic and he said the additive is for older diesel engines not the newer engine with the DPF. Is this true? Should I use anything other than fuel?