Originally Posted by Jason

I don't have direct knowledge, but I can just about guarantee it. Not only would it likely void your warranty, but you may be physically unable to pull the trailer. It's possible the entire hybrid system will shut down to prevent you from doing damage.

You'll find this a good read. Note that while the Escape doesn't use Hybrid Synergy Drive, it uses many of Toyota's patents and is a very similar system.
http://www.greenhybrid.com/discuss/h...arts.2208.html