Shortly before I sold my WRX I sent in a sample of coolant to be analyzed. At 15350 miles on the car and the factory fill coolant, I drained, flushed, and filled with a 50:50 mix of regular Prestone and distilled water, with a small container (maybe 12 oz.) of Prestone Rust Preventer. At 30569 miles on the car and 15117 miles on the Prestone, I drained, flushed, and refilled with Subaru coolant and water. This sample I am about to post is on the Prestone coolant.
code:That is all that was listed as being analyzed, and there was the typical OAI/CTC comment "Test results performed indicate no corrective action required" I have no understanding of coolant analysis, so I am pretty dependent on their comment. As the car is sold, it is also pretty much irrelevant to me. The WRX has an aluminum block and heads, iron cylinder liners, and an oil:water oil cooler. The turbo is also water cooled.Sodium 2570 Phosphate 689 Molybdenum 39 Iron 2 Copper 6 Lead 0 Aluminum 36 Boron 373 Silicon 73 Silicates 0 Nitrates 817 Nitrites 674 Conductivity Meter (D-4308) Conductivity 3250 uS/cm TDS 944 mg/l