MPEG-1 to MPEG-4 Conversion Benefits

[quasims]

I am new to this board and to the world of DV... i saw an article about DivX/MPEG-4 encoding boasting that it can compress MPEG-2 to 1/11 of it's size... I realized that it should convert MPEG-1 as well... so I wanted to convert my old VCD's to MPEG-4 and store them on one CD... (and the article actually said that a 110 minutes movie can be stored on a 80min CD-R conviniently). But i could only reduce MPEG-1 to 60% size despite using the latest DivX 5.0.1 codec... was pretty dissappointing for me... i now have a few questions in my mind...

Can any of U guys give me a URL to "conversion basics" for definitions like bit rate, etc.

Is the conversion process from MPEG-1 to MPEG-4 "lossy" or "losless"?

Are there any benefits of using MPEG4 except smaller size...?

Thanks

[ChrisG]

Conversion from MPEG1 to MPEG4 ist lossy!

I have converted a DivX movie with 640x480 to DivX again with 512x384, nearly same bitrate. The 512x384 file looked very bad!