On Fri, 19 Mar 2004 15:10:48 GMT, "Doug Kanter"
wrote:
Actually, the stability of the towing vehicle has a definite effect on
mileage. If the trailer is horsing the car around, causing all sorts of
sideways motion, the engine's going to work harder to keep things steady.

==================================

I agree that there is a possible relationship but it's mostly minor
and irrelevant. Tuning the tongue weight for directional stability of
the entire rig is the main priority. Too little tongue weight and the
trailer will start to fishtail at some point; too much and the tow
vehicle goes nose high with light steering and an overloaded rear
axle. I went through all of this last year with a new trailer and it
took several iterations before it was right. Fuel efficiency never
entered the discussion at any point.