The broadcaster blamed the lack of an accompanying TV presence for the closure of the site, which was launched to support hit show Driven.
Dan Gilbert, editor of 4Car, said via the Channel 4 blog that the site faced too much financial pressure.
“Unfortunately the current economic climate has made it difficult to keep the site running, especially without the justification of an accompanying TV show,” he said.
“In light of the large running costs and downbeat commercial market continuing into 2010, we have reluctantly decided to close the site.”
Rival broadcaster Sky axed its car site Sky Motoring in September, citing commercial issues.
This story first appeared on newmediaage.co.uk