Agree on air purging. After filling my 1984 300D with Evans Waterless Coolant, after driving 6 miles on the freeway, the dash temp gage suddenly began climbing fast. I pulled over right as it hit the 120 C redline. I had to add a half gallon of coolant to top it off. No coolant loss and no more overheating, even climbing the Sierras on a hot day. I don't think the engine really got that hot, but rather the temperature gage shows hot if in an air pocket.