Quote:
Originally Posted by NeilBlanchard
Here's a counterpoint:
Weight is important, but not as important as drivetrain efficiency, or as aerodynamic drag. The reason is, that as you note weight adds to the kinetic energy, so you can reclaim it by coasting, and/or by using regenerative braking if it is a EV. So, yes it takes more to accelerate, but you can get back some of the energy you put in; preferably by coasting.
Aerodynamic drag though, is a total loss. And rolling friction (like wheel alignment, bearing friction, dragging brakes, and tire rolling resistance, etc.) are also total loss; but they are also fairly easy to minimize.
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Ok good point with reguard to coasting but, please consider that weight makes bearing friction worse and also it presses the tires down to make rolling resistance worse. If you try to fix it with lighter wheels they will be crushed at the next pot-hole. Regenerative systems will return a fraction of the energy spent.
I got a ride in a car that was 1400 lbs over weight and despite what people might think, the Leaf which is built lighter will go twice as far and the Tesla roadster 4 times as far because they built it very light. The same can be said for the British mini that reduced weight by using wheel motors. 280 miles on a charge is very good! 50 miles on a charge is a lead weight on wheels. So you see, I am just makeing some real world observations as to what has produced results and what has failed.
If you try this out on a bicycle you will get a better feel for what is going on.
First ride 8 miles with out any weight in your back pack. The next day, carry 100 pounds of lead in your back pack and make the same trip up and down hills. Reclaim the energy that your legs put in when going down the other side of the hills. The ride will be very difficult on day two and you will feel it in your legs.
I have had my hands into the construction of two aircraft and believe it or not, all of these factors are important for any vehical.