David is correct, 3 rows of tubes is definitely the way to go. They also make two styles of fins, the regular one is rectangular shaped with flat fins, there is a higher efficiency one that has a 6 sided shape and even has some twist to the fin to create turbulence and promote higher heat transfer. I opted for the 3 row with the regular fins; it cost $425 in Houston 2 years ago and it works great in 100 degree F heat. (no AC and standard transmission)