I have been since I got the car. Putting the heat on full death valley mode. I have noticed it will move the water gauge about two ticks to the left from the middle than I shut it off. The wife will do this to help cooling down the engine oil and prevent turbo failure. The wife and I haven't been able to get a turbo timer just yet. So I have her just do this. Anyone else do this? Or am I nuts lol. The fuel mileage suffers a little. Yes, diesel is expensive. But who is counting anyways. I also switched to the Summer blend of Power Service.