The aluminum radiators that have been designed over the last few years have wider and thicker tubes in them. Its said that some of the tubes are 1" wide and nearly 1/8" thick. They say that the wider the tubes, the more efficient the cooling process is. They also say that adding more rows of the small tubes becomes less efficient with every extra row added past the standard 2 row radiator, a 4 row is not 2x as efficient as a 2 row is. it is just slightly better then a 3 row. Most of the existing aluminum radiators have not been updated to the modern tube designs.

So now the concept is to have two rows of offset wider and thicker tubes per core is as efficient as it can get. The wider and thicker tubes also greatly improves the strength and structural integrity of the aluminum radiators.

The technology for brass & copper radiators has not advanced since the early 60s when they were in their prime time, the only thing they have done with the brass and copper radiators is thin the material used in the production which lowered the strength of the brass & copper radiators. Modern wide, thick tube, 2 row aluminum radiators are more efficient then 4 core brass and copper radiators are, and cost less. If that aluminum radiator has a "furnace welded core" with no epoxy, it is a better quality radiator.