On Fri, 26 Oct 2012 02:03:02 +0100, Clive George
wrote:

The weight is rather less important than you might think. Consider a
truck going a constant speed down a motorway for ages - where are the
losses? Weight is important for acceleration, but once you're at a
constant speed none of that is going on.

The vast majority is air resistance, and that's not going to be much
more at all for the bigger trailer - same frontal area, no massive
difference in shape.

There will be some rolling resistance, and a part of that will be
proportional to weight, but it'll be swamped by air resistance.

First find a motorway without any hills


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