What zip archive format will give the smallest file size?

Ok, here's what I got. I have archived the same file over and over again to ensure accurate results.

The smallest archive format is apparently a .7z archive.
Here is my list of smallest to largest archive formats of a 1,684 KB file.

Archive Extension Size

7-Zip .7z 1,428 KB
RAR .rar 1,431 KB
G-Zip .gz 1, 473 KB
Cabinet .cab 1,474 KB (TIE)
Black Hole .bh 1,474 KB (TIE)
JAR .jar 1,474 KB (TIE)
ZIP .zip 1,474 KB (TIE)
LHA .lha 1,477 KB
BZA .bza 1,504 KB (TIE)
BZ2 .bz2 1,504 KB (TIE)
YZ1 .yz1 1,514 KB
Uncompressed .exe 1,684 KB
TAR .tar 1,690 KB

There you go. Apparently TAR actually makes the file bigger. So don't use TAR I guess. I spent quite a bit of time doing this so I hope it will help a lot of you out there with the same question!