My old cummings only requires the green stuff so I use Super Tech from Walmart. Yes I changed my fluid about 4000 miles ago and the thermostat. The thermostat was stuck which caused overheating. Sure doesn't overheat now....very cool. Also the mixture was way above 50/50 so I am ok now. My number is 352-683-0490 and e-mail is
tharris@gate.net. What I did was measure the amount of fluid that come out and put the same amount back in. It was 18-20qts. I measure it so I would know that I didn't leave air bubbles in the system. I run mine with the cap off at idle to make sure the thermostat opened and allowed proper circulation. My engine idles at 182 and increases to 187 under load on the straights. Goes up to 192 on small hills. Far cry from the 215 I was getting.