Anyone Using Amsoil Propylene Glycol Coolant In Their Diesel

Since you have a Cummins, I would also go with the Fleetguard ES Compleat OAT: http://www.cumminsfiltration.com/html/en/products/cooling/coolant/es_compleat/oat.html

If a Caterpillar, Caterpillar ELC: http://catoilandgas.cat.com/cda/files/760484/7/PEHJ0067-02.pdf

Both are basically "put it in and forget it" unless you drive more than 300,000 miles between changes in which case a one time additive is needed.

That way, if you are ever in for engine service, they will have the correct coolant on the shelf.