If you're new to caravanning, understanding the different weights of a caravan is crucial. Tare weight is the weight of the van unloaded. GTM (gross trailer mass) is the maximum weight of the fully-loaded caravan. And ATM (aggregate trailer mass) is the maximum weight of the van, fully-loaded, and with the car's weight on the tow ball. Understanding these weights will help you determine what car can tow your caravan and how much weight you can safely put in the van. Save this video for future re