Not only did aluminum resist rust and corrosion, but it was also lighter and therefore easier to pull.
Compared to steel, the aluminum used in all-aluminum trailers is an alloy, the same way that steel is an alloy of iron. This alloy has about the same yield strength as steel! It contains at least 95 percent aluminum, and the other five percent is composed of copper, titanium, chromium, and zinc. Other metals are also added in trace amounts to further refine the alloy’s properties.
The lower weight of an aluminum trailer also translates into a higher payload capacity, meaning you can load more items into an aluminum carrier before reaching the maximum amount of weight your vehicle will tow. Finally, as previously mentioned, several trailer owners reported better gas mileage towing an aluminum trailer than they did with a steel one.