I took a look at the some explanations about
the way TCP/IP packets work and it proves you are right: there are three parts compounding a Transmission Control Protocol/Internet Protocol packets: the header, the payload and the trailer.
Now, the explanations in the above-mentioned Web address point that
the header is three times bigger than
the trailer (32x3). If you add their value (128) to the size of a kilobyte (1,024), you will get 1152 bytes, which is 8 bits shorter than the number that the optimization company suggested as appropriate (
1160). So it seems that the 1160 value (32 bits header + 96 bits trailer + 1024 bits payload + 8 bits
perhaps for additional information) is justified.
But anyway, the main idea is that a CSS should be smaller than 8K. You might want to compress your Web site's content using the
mod_gzip compression module. It compresses the information being sent to the visitor, for faster Web site-loadtime.