I had never used any fuel system cleaners in my Durango, which has 104,000 miles on it now. I'm not sure if the previous owner did either, so last night I went to Wal-Mart and picked up two bottles of Regane and a bottle of Lucas UCL, and dumped all of it into 25 gallons of Shell gasoline.
Not sure if what I did was the absolute best thing for it, but I'm sure it didn't hurt anything. Once I get a few miles on this tank, I'll be able to see if anything good came about from it, or if I just dumped 17 bucks out the tailpipe.