I posted a thread last week in regards to a coolant leak. Just found out that it is the water pump. There are also 1 other 2018 & 2 other 2017's at the dealership with the same issue. I asked what the deal was & the SA commented that Porsche uses a variable speed water pump for efficiency in the 991. When I pick it up (hopefully soon) I will get clarification on the root cause. I wonder what it would cost if it was not under warranty? Kinda scary...

Variable speed makes sense. People are reporting oil temps in the 220F-ish range in Normal mode and it drops down below 200F in Sport mode. So what is likely happening is higher water/coolant flow which means more to the oil cooler keeping the oil cooler. Warmer oil in Normal mode makes it less viscous and gives better fuel economy. Any pictures of where the coolant was leaking from?

Edit: it seem the variable part is mainly for cold start. It essentially does not flow coolant so the engine warms up faster thereby reducing emissions and fuel consumption.