[89-944NA]

Distilled water also negates the need for phosphate free antifreeze, as there are no dissolved solids in distilled water. I have warrantied many water pumps in my dealings with Porsche 944's etc, and never had a warranty refused because I didn't use phosphate free antifreeze.

The only vehicles that Porsche is very strict on coolant is the newer water cooled head engines, 996, Boxster, Cayman etc, and they REQUIRE the use of Porsche Coolant.

As I said earlier, the phosphate free antifreeze is only required in countries with water that contain high levels of dissolved solids (hard water). Also, in discussions with a senior manager with PCNA and the Head Technician (30+ years) at my local Porsche dealership, both stated that phosphate free antifreeze is not required in the United States due to our better quality (softer) water than most countries, but the expense of changing the wording (to delete the reference to phosphate free antifreeze) in owners manuals for US cars was not deemed necessary.

Also, distilled verses tap water is NOT A REQUIREMENT, but a personal preference (but yes, I do use distilled water). My car never runs over the lower mark on the temp gauge unless I am stuck in the aforementioned LA traffic, where it may rise to the middle of the gauge.

Gentleman, what we are discussing here is more personal preference than hard fact, and we have strayed from the original posters question, "Any comments on issues/problems on using non-Porsche coolant?"....

In a nutshell, there are NO ISSUES with using "aftermarket" coolant in our pre-1997 water cooled cars, other than the actual cost of the coolant itself, "aftermarket" coolant about $12.00 per gallon, Porsche coolant $36.00 per gallon. Your preference and wallet will decide which you should use.