When did yo hear that Franky? As far as I knew (about this far: holds fingers close together) Scawen hasn't actually attempted to make the AI aware of the dynamic car state or fuel loads, so far from being too difficult, he just hasn't tried yet!!!
But, as LFS is an ONLINE racing simulator, that you get ONLINE, and unlock ONLINE, it's a wonder people are really bothered about the AI. If I drive offline, it's either hotlapping or long runs on my own in preparation for a proper online race!