In rec.aviation.piloting Morgans wrote:

"Dan Luke" wrote

Pardon the intrusion on this interesting discussion, but just how *does*
added weight in a car impose extra load on the powerplant besides via
bearing friction and tire deformation?

It isn't. He failed to include bearing resistance (only tire deformation)
in the original assessment of increased rolling resistance.

I didn't include it because the increase in wheel bearing friction (the
only bearing friction effected by weight) is negligable in modern
vehicles.

The total bearing friction, i.e. all the bearings in the vehicle is
around 10% of the total drag forces trying to slow a car.

Adding a little weight to a 2000 to 3000 pound car causes an insignificant
change in the wheel bearing friction.


--
Jim Pennino

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