What are some additives that are safe and effective for the 05' cummins and what are some that I need to stay away from? Thanks

 

You need to type fuel additives in your DB search. this is a subject that creats a long standing debate that is very opinion driven. You don't need a bunch of ODD stuff!

 

I run Opti Lube Summer Blend and love it. It came in #4 out of 20 in a test. Based on a 26 gallon tank it cost around $0.68 a tank because of it's high concentrate. I recently drove to Ga. & did my own test with and without I honestly picked up between 2-3 MPG on highway. I bought it for injector protection more than anything and this is a bonus.
Opti-Lube Summer Blend Diesel Fuel additive blend, Opti lube, Optilube