After cleaning the throttle, antifreeze is consumed quickly.

There is no connection at all. Antifreeze is consumed quickly unless there is a leak. Don't think about the throttle.

In the past, some water was added to the antifreeze every 4 s maintenance. Recently, because no water was added for more than a year, the antifreeze dropped by several centimeters, which should be normal. Think of other reasons.

In addition, the liquid level of hot car and cold car is different.

If it is determined that it is only normal loss, just add some distilled water.