I have noticed on my 221.176 that the coolant temperature begins going up very fast after start. Is the coolant flow restricted during startup to allow the engine to reach operating temperature? Are others seeing this? It never gets too warm or overheats and never has - it only rises quickly, as in seeing the needle move off of the resting point of 40°C while driving down the driveway.

V-12's warm up quickly. The thermostat restricts coolant flow until the engine is warm, just like it does on every car/truck.

So this is typical for this engine. That is good to know. I wasn't sure if there was anything different about the design of the M275 to cause this or typical for it.

Remember, on your car the gauge is strictly an electric display. It's what the M/E wants to display. The car does warm up quickly as emissions regulations force the manufacturers to get the engine as hot as possible as quickly as possible for optimum converter funcitons. But there are many cases where what the gauge displays and actual engine temps can differ. As long as the car isn't getting overheated, there's nothing to worry about. A slow warmup doesn't really help anything anyway.