I think you meant to say wider tubes. Wider tubes allow for more uninterrupted contact with the cooling fins. The most efficient radiator will have 1 row of 2" wide cooling tubes (Nascar),but that isn't a realistic option for us because of the price. With 1 wide tube you have contact with every bit of the cooling fins. When you have 2-4 rows of tubes,you have spaces in between the rows where the fins aren't contacting any tube and there is turbulent air created between the tubes as the air passes through the open spaces. This all speaks to efficiency. For the average Joe,2 rows of 1"wide tubes is the best cooling radiator.