How about using an adequate sized, oil laden fluid coupling for engine dyno use,(industrial applications) ? Seem to be much cheaper than water absorbtion units. These use oil inlet/ outlet, for amount of slippage. What if ? Thanks, roverman.
You checked your tire pressure at 9k feet altitude. You check again at sea level,(same gage/same temperature). Did tire pressure increase or decrease ? Food for thought, roverman.
Increase, accordingly increased atmospheric pressure.