Are there any tricks for getting a bit more old coolant out of a 2015 era Vantage V8 via the drain plug? I did a partial coolant change a month or two ago. However, only about 4 L came from the drain plug (quarts and liters are approximately the same) that left 10 L of original fluid remaining. About 1L more came out when I took the thermostat out. I replaced my levels with 50/50 factory fluid, but it was not a satisfying job.

Are there any tricks for draining more of the old fluid. For example, is there any potential damage from fully draining the radiator, leaving the plug open and then running the car for just 60 seconds to spin up the coolant pump and refill the radiator for a further draining? Alternatively, it has been suggested to do the change twice in rapid succession with a short drive between. Still, that is not great either 4L from 14L repeated.

Reading the other posts, the amount of fluid that comes out from an Aston is highly dependent on the model and still variable, but 4L is on the low side of most peoples experience.

Thanks

Philip