My 03 came with gold coolant. Can you mix the orange coolant together? It is labeled on the bottle as equivalent to Motorcraft gold.

 

As long as it is labeled GO-5 you can add it to the factory fill of the gold stuff. Zerex makes the GO-stuff found at Auto Zone, etc.

 

Green + Gold = BAD
Orange (Dex-Cool) + Gold = BAD
Gold (Ford) + Gold (Zerex G-O5) = GOOD
Gold (Ford) = GOOD

The Gold already has the anti-cavitation additive in it Plus it's for 5 years.

 

best bet dont mix coolants stay away from the green stuff period
make sure you run a coolant that can maintain the correct nitrate levels when it does come time to replace your coolant I recomend going to either the caterpillar extended life coolant comes pre-mixed good for 500,000 miles this is what I run in mine (its red)
or fleet guard extended service (blue) both are outstanding coolants and keepyour cooling sys in top shape tou can pick them up at most truck stops or reputable heavy truck shops for around
7 bucks a gallon