[basjoos]

Since the weight of a cubic foot of air at sea level and at 70 degrees F is 0.07495 lbs, the mass of air displaced by a vehicle with a frontal area of one square foot driving a distance of one mile is 396 lbs.

So this means that my 92 Honda Civic CX (frontal area 19.9 square feet) displaces 3.9 tons of air for each mile it drives down the road at sea level and at 70 degrees F.

Drop the air temp down to 0 degrees F (0.08637) and the weight displaced goes up to 4.5 tons/mile.

Raise the temp up to 100 degrees F (0.07094) and the displaced air drops to 3.7 tons/mile.

Drive from the coast to my home altitude of 500 feet (assuming the temp remained at 70 degrees F) and the weight of displaced air drops to 3.8 tons/mile.

Continue driving up to Asheville in the NC mountains (2000 feet) and it drops to 3.6 tons/mile.

Head on up the road to Denver, CO (6000 feet) and I get 3.1 tons/mile.

Climb up into the Rockies to 10,000 feet and I'm down to 2.7 tons/mile.

An interesting intellectual exercise and directly shows the effect of temperature and altitude on your mileage