Ford 2003 Mustang Workshop Manual page 1899

NOTE: The addition of Motorcraft Cooling System Stop Leak Pellets, VC-6, darkens Motorcraft
Premium Gold Engine Coolant from yellow to golden tan.
Add Motorcraft Premium Engine Coolant VC-4-A (in Oregon VC-5, in Canada CXC-10) or
equivalent meeting Ford specification ESE-M97B44-A (green color), or Motorcraft Premium
Gold Engine Coolant VC-7-A or equivalent meeting Ford specification WSS-M97B51-A1 (yellow
color). Use the same coolant that was drained from the cooling system. Do not mix coolant
types.
Do not add/mix orange-colored Motorcraft Speciality Orange Engine Coolant VC-2 or equivalent
meeting Ford specification WSS-M97B44-D. Mixing coolants may degrade the coolant's
corrosion protection.
Do not add alcohol, methanol, brine, or any engine coolants mixed with alcohol or methanol
antifreeze. These can cause engine damage from overheating or freezing.
Do not mix with recycled coolant unless it meets the requirements of Ford specification ESE-
M97B44-A or WSS-M97B51-A1. Not all coolant recycling processes meet these Ford
specifications. Use of such coolants can harm the engine and cooling system components.