Doh

by reduction you could argue that it makes no sense that a vehicle
gets better fuel economy at 70 than it does at 60. As you indicate,
it's all to do with gearing.

yes, I said that already.

 

It depends on the dominant drag mechanism. By the time you get to 80,
unless the vehicle is very badly designed, most of the incremental
drag will be aerodynamic. That is not necessarily true at 60.

 

OK, yes, I know the basic power equation is something like

required power = av + bv2 + cv3

where a is the linear rolling resistance (tires, drag from brake pads,
rotating engine components)
b is energy lost from pumping/cyclical engine parts &
c is air resistance

however, empirically, judging from the real time fuel consumption
indicator in our Jeep, it is more fuel efficient at 80 than 70, but
after that it drops of *really* fucking quickly.

 

Crossing of curves and shit innit. One going up and one going down or
something?

 

In the best traditions of UKRM then.
<googles>

There really is some fascinating stuff on the interwebby about all this
isn't there?

At least it's gratifying to see that my empirically derived position on
the high gear for economy question has some theoretical basis.

Right Answer Wrong Explanation. Is that worse than RAWQ I wonder?


--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Oh, that'll be why car manufacturers have never fitted overdrives in any
cars, ever.

Fur ****'s sake, I don't think I've ever read such a load of bollocks.
--
Dave
GS850x2 XS650 SE6a

Teach a man to fish and he and his pikey mates will have the
river cleaned out in a day.