Howdy On cleaning up carbon build up I was taught to get the motor hot than pour in a 1/2 quart ice cold water and ATF mixture, while keeping the RPM's high. This was the first thing that I did to every Mopar that I bought in the 70/80's. On winter storage I treat the fuel than I park them, I only start them if I can drive them at least 100+ miles. Case in point I fired up our 09 Charger SRT and we went on a 250 mile ride, our 15 Scat Pack and 70 Convertible. are still hibernating.