Do you need fuel additives, No you do not need them. But there are a few reasons why you might want to use fuel additives. I use them because i like some of the benifets they supply. Extra lubrication for the pump. Keeping the injection system clean. Reducing deposits, black smoke, emissions, and injector wear. Also in the colder climates they lower the fuels gel point. I like to use the AMSOIL line, CETANE BOOST, and DEISEL FUEL ADDITIVE. I have used them since 97', and have had very good luck. While towing I can see a reduction in EGT's, and it just pulls better. I have to get E-CHECKED every other year, and they always note how low my numbers are, always . 1 ppm, when the limit is 10 ppm. I haven't had any fueling related issues, and I kind of like that. When I'm on the road, and don't have the time to add the additives, you can fell the difference, mainly if I am towing. Just my . 02, take it for what it's worth.