In the ordinary course of driving a car, the wheels need to be
supplied with power. This is required for accelerating, maintaining
speed against friction, and for gaining altitude (when driving up
hills). The wheels also prevent the underbody of the car from
crashing into the ground. Vehicle design systems do not explicitly
state whether the wheels need power to carry out the latter part of
their function. It is assumed that people know that they don’t
However, if the wheels are constructed from something that does not have the material strength to support the weight, “bad things” will happen.
In the ordinary course of driving a grav vehicle, the grav plates need
to be supplied with power. This is required for accelerating,
maintaing speed against friction, and for gaining altitude. The grav
plates also prevent the underbody of the vehicle from crashing into
the ground. Vehicle design systems do not explicitly state whether
the grav plates need power to carry out the latter part of their
function. Unfortunately this time it cannot be assumed that people
know whether or not they do, because it's imaginary magical
technology.
I think that’s the confusion here. Most things we look at today either use material strength or force (like air being displaced) to counteract gravity.
ContraGrav uses pixie dust.
If you want to be able to part your Grav Tank and have it just float there, great. Add more pixie dust.
If you want it to have to “land” then use a little less.