Fungus is like the clapp: You don't geyt it unless you get exposed to it. Fungus doesn't come out of the air: you have to get fuel contaminated with it. So what is I'm saying is that Biobor is not preventive mintenence. Its only needed if you have a fungus contaminated fuel system.

I have been using Diesel engines for 40+ years and only has a fungus problem one time. That was in my '80 300SD that has been in all the startes less one. Someplace in those travels, I got contaminated fuel and had to use Biobor to kill the fungus.

Since using the Biobor 10,000+ miles I had to replace one inline fuel filter and did no other cleaning fo the fuel system.

P E H