A vote for FPPF here. I have always used this product since my truck was new (12 miles on the ODO). I don't think I have ever missed adding it to a tank. Now with 202,000 miles and the only issue in that entire time has been one replaced injector at aprox 170,000. Mileage hasn't changed a bit in that entire time.

Also, fuel filter changes every 10,00 regardless of what the computer tells me. Oil and filter changes every 5,000 and transmission fluid and filter changes at 25,000.

Oil and filters are cheap, engines and transmissions are not.