I've heard there's a 20% loss of power through the drivetrain on autos and about 15% on manual trannys.
There is also a substantial loss because of altitude. Don't know the number but I'm guessing another 10% at 6,000'. The reason altitude zaps power is because of two things, atmospheric pressure, which at 6,000' is 13.8 (sea level is 14.6). So cylinders have less pressure and compression here. We can run 87-91 octane in a 10-10:5.1 compression car.
The other factor is oxygen density. We have considerably less oxygen molecules per million than at sea level. I don't know the number, but that is why the Olympic Training Center is here, just down the street. Athletes come here to train in the oxygen depleted air to build up extra hemoglobin (the part of the blood that actually caries oxygen through the body). Then when they go to a lower elevation, they have extra hemoglobin to take advantage of extra oxygen. Ok, Physiology 101 is over… :ack: