The initial fill is different but you need that to determine how much antifreeze you need. After talking to our local Cat dealer and two other service companies, I got the same answer about changing the antifreeze. Drain all you can get out of the system and refill with distilled water, run the engine with heater on for about 90 minutes, drain and repeat then drain again. Put in enough concentrated antifreeze to equal 1/2 of the initial fill and then top off with distilled water and add the addatives. Run again for about 60 minutes and test. My mix came out at a 50/50 antifreeze/water and nitrates etc were perfect. They all recommended staying with the antifreeze you have in( ELC or regular).
The Cat dealer said that if you are going to change to ELC you need a chemical flush and several additinal distilled water flushes to absolutely remove all old antifreeze or you will contaminate the new ELC. They sell SHELLZONE concentrate to replace regular antifreeze. I found out that our local cummins dealer also makes the same recommendation and also sells the SHELLZONE. Just my experience with antifreeze. I'm sure there are other opinions . I just follwed the advice of the Cat shop foreman.
Roger
