Nissan 2007 Pathfinder V6 4.0L factory fill coolant at 33500 kms. From the reserve alkalinity how much longer would this coolant be safely useable.

Is the P potassium?

K is potassium. P would be phosphorus, surely from phosphates.

Asterix

If you check out my thread on the Freightliner M2 coolant analysis, the PH level of 7.6 was flagged as low. Yet this Nissan coolant with PH of 7.3 is considered normal and acceptable. What gives? Diesel engine coolants have to be more alkaline than gasoline engine coolants?

Japanese coolant chemistry was developed for cooling systems where aluminum is the primary metal; it is completely different from North American coolant chemistry. Japanese coolant has a low pH (7.5-8.0) because it is less corrosive to aluminum than high pH (10-11) coolant designed primarily for cast iron components.