Can zerex g-05 be used in a 1999 5.4 liter f250ld if a radiator flush has be done and all the old antifreeze has been removed?

 

Older trucks came with the standard GREEN antifreeze.. Trucks in our age came with the new "YELLOW EXTENDED LIFE" type antifreeze. I believe G05 falls into that category. You can mix the yellow with the old green, but that dilutes the advantage of the yellow... best to drain, flush , then refill.

Most GM vehicles for the last 10-15 years and NEW FORDS about 2011- UP come with the "Extended life ORANGE" .... that does not mix well with others, and modifications are needed to internal parts to make it acceptable to use the ORANGE.

Stick with the EXTENDED YELLOW and you will be fine.