Ive been using seafoam for years. Havent put it in the Mustang yet. I typically I start using one can about every 4-6 months once the engine gets to around 30-40K on the odometer.
Oil Gunk remover saved me over 4K in engine work from Honda when my 05 accord started going into limp mode at 80K. The filter for the ivtec system became clogged and honda wanted to tear the engine down and rebuild. One $6 bottle later and the clog was gone. That was 40,000 miles ago.
2012 Race Red GT Premium | MT82 3.31 | HID/Security | Steeda CAI | BAMA 91P | JLT Seperator | Steeda Shift Bracket | Steeda ProAction Shocks/Struts | Steeda Heavy Duty Strut Mounts | Eibach Pro-Kit (Dub) | J&M Adj. Panhard | GT500 Axle-Backs w/Resonator Delete | Ford Racing STB | American Muscle GT500 Black Machined 18x9/10 Nitto 555