winrar has more efficient compression than gunzip

I had a .gz folder, G093_7200001_ENU.gz, size 48.9 MB (5,13,57,060 bytes).
I uncompressed it using winrar.
The extracted folder, G093_7200001_ENU, had size of 92.0 MB (9,65,23,264 bytes).
I then compressed G093_7200001_ENU folder using winrar.
The compressed folder is G093_7200001_ENU.rar, size 37.6 MB (3,94,89,700 bytes).
I uncompressed it using winrar and made sure that the extracted G093_7200001_ENU, had size of 92.0 MB (9,65,23,264 bytes) as well.
Thus, .gz file had a size of 48.9MB, whereas, .rar file had a size of 37.6MB. Hence, winrar has better compression than gunzip.