Of course, it's possible. As I said, our Honda Civic is now 16 years old, and it gets 40 mpg.

Our Honda Odyssey (minivan) gets 30 mpg without a tow and 24 when towing two boats double-stacked -- even up and down over mountains.

For some reason, auto manufacturers (at least in the U.S.) do not seem to be highly motivated.

As I think somebody mentioned earlier, this is very relevant to sailing, because the high price of fuel, combined with low mpg for towing vehicles, is hurting regatta attendance.