I'm a DCA dummy........
On my Ford powerstroke they recomend the water additive to remove bubbles and aid in cooling. I have seen a block where a water bubble has etched through a cylinder wall rendering it useless I would never beleived it if I hadn't seen it my self.. Most diesel engines recomend this. It sounds silly but the expence of the additive is well worth the pease of mind. As to its abilty to cool better I wouldn't argue that. I buying it any way I think it was about 20 bucks for a 20 qt. cooling system and it last several years. I just add every time I flush the system.
Now, you just got in my territory.....
It's not a water additive. It's DCA. What it does is cause the coolant to flow over the cylinder liners without causing impingement. You only need it for a wet linered engine (read R3). Impingement is when an air bubble forms on the side of the liner and implodes due to heat and pressure. That implosion causes a pit in the outer wall of the liner which eventually eats through the liner and causes a catastrophic failure to that cylinder. You actually have a couple of choices. You can use the Ford additive, buy the Cummins DCA4 pre mixed additive, buy pre-mixed pre-charged antifreeze or completely drain and flush the system and go with long life pre-charged antifreeze. There is also the option of an external coolant filter with a "need-release" block of DCA additive inside. That's what I use. The filter cleans the coolant of scale and keeps the Ph in check while keeping the DCA at the correct level. I still use a Ph test kit to check the alkalinity level and the silicate level on all my wet linered diesels.
Never mix regular Glycol antifreeze with long life antifreeze. They aren't compatible and the antifreeze will turn to jelly.
Big no-no.
For the occasional user like you, I'd recommend Cummins DCA4 pre-mix in 8 oz bottles. All DCA4 is, is deionized water, trace chemicals and potassium permagnate, Ph adjusted. The DCA level drops within the engine during heat/cool cycles so it has to be replenished. That's where the test kit comes in handy. It baselines your DCA level as well as Ph and allows you to determine whether you need more DCA. Too much DCA is as bad as too little.
In all actuality, you should be able to pre-charge a Powerstroke with normal, no additive glycol antifreeze with 3 8oz. bottles of DCA4 at 4 bucks a bottle. The Ford stuff is re-packaged DCA4 at an inflated price. Cummins and Fleetgard are the best buys. Fleetgard is owned by Cummins as is Onan.
If you need DCA or a test kit, truck up to GR Freightliner, they have it. If they don't have the test kit, have them get it from us. The comprehensive test kit is around 50 bucks but it will outlast your truck and your next one and your next one. It'll be in your estate sale.
An added benefit of DCA is it controls solder bloom and scale formation because it controls the Ph of the coolant. I'm going to add a few ounces to the R3 before it gets back on the road. I'd put a coolant filter on, but there is no room. You can get coolant filters in the need/release design or what we call a dummy filter. Just filter media and no DCA.
The impingement factor only comes into play on a wet linered engine. Parent bore or dry linered engines don't suffer from impingement (read Duramax and Dodge/Cummins). A wet linered engine is better in some respects than a parent bore. A wet linered engine is better able to transfer combustion heat and at re-build time is easier to re-build. Liners aren't pressed in like a parent bore. They locate on a ledge and are sealed with packing. The head actually provides the clamping force. Parent bore liners have to be pulled, usually hydraulically or by shrinking and the new liner has to be pressed in or shrunk and inserted.
I know that's technical. Just get some DCA4 next time and a test kit and save some bucks.
