From: geoff@peck.com (Geoff Peck)
Newsgroups: rec.aviation
Subject: Re: Flying saves money (sic)
Keywords: money
Date: 27 Aug 92 02:12:47 GMT
Organization: Geoffrey G. Peck, Consultant, San Jose CA

This question comes up with some regularity.  For U.S. pilots, at least,
it's interesting that if one takes into account the *full* cost of driving
vs. the *full* cost of flying, on a per-mile basis, flying a typical light
single is indeed comparable to driving a late-model car.

Nuts, you say?  Here's the arithmetic.  Note that the cost of capital
(financing) is not included for the owned vehicles.

Automobile (owned, driven ~15K miles/year)

    Cost = $25K, residual value after 100K miles = $5K.		$0.20/mile
    Fuel = $1.20/gal, 25mpg					$0.05/mile
    Regular maint = $100/7.5K, $200/15K, $100/22.5K, $300/30K	$0.02/mile
    Tires = $400 / 40K miles					$0.01/mile
    Registration (California), 5 years over 60K miles           $0.06/mile [3]
    Insurance, $1300/year, 15K miles/year			$0.09/mile [3]
								---------
								$0.43/mile

Airplane (owned, 150mph class, flown a mere 100 hours/year -> 15K miles/yr)

    Cost = $40K, residual value after normal use = $40K		$0.00/mile [1]
    Fuel = $2/gal, 10gph					$0.13/mile
    Maint = $1600/100 hour insp + $200/50 hour insp		$0.12/mile [2]
    Reserve = $15K/2000 hr engine, $3/hour other                $0.07/mile
    Registration (free) and Taxes (California, $500/yr)		$0.03/mile [4]
    Tiedown: $76/month						$0.07/mile [4]
    Insurance: $1300/year					$0.09/mile [4]
								----------
								$0.51/mile [4]

Automobile (rented, major company, daily basis, 100 mi/day = 36500 mi/yr!!!)

    Intermediate @ $42/day, no mileage charge, drive 100 mi.	$0.42/mile
    Gas = $1.20/gal, 25mpg					$0.05/mile
								----------
								$0.47/mile

Airplane (rented, FBO, daily basis, fly what you will)

    C-172/Warrior @ $50/hour wet, 120mph			$0.42/mile

Notes:
    [1] Airplanes actually have been *appreciating* for the last several
	years.  If you buy an airplane and maintain it well, you should be
	able to sell it at a *profit*.  We won't take that into account
	here.

    [2] I'm using rather high figures here for maintenance.  These could
	easily be reduced by a factor of 2 or 3 if you (1) owned a simpler
	airplane or (2) did some of your own maintenance.  But you could also
	take similar economizing measures with a car.

    [3] Yes, you probably will own a car anyway.  (So, you _should_ own an
	airplane anyway! :-) )  So the fixed costs of automobile ownership
	like registration and insurance maybe shouldn't be counted -- they're
	"free".  So do your own set of numbers.  Or buy a bicycle.

    [4] The fixed costs of airplane ownership are quite high.  If you
	Fly this very same airplane 250 hours/year, still doing 100-hour
	inspections, the cost drops by $0.11/mile, just changing the per-mile
	costs of registration, taxes, tiedown, and insurance.  This drops the
	total cost to $0.40/mile -- a clear winner!

Now, you protest, "But wait!  He just showed that it costs $.51/mile to fly
and $.43/mile to drive!  How can flying be cheaper than driving?" Well, if
you look at the *rental* 172, it's $0.42/mile.  In the case of airplanes
(which at 100 hours/year are underutilized resources), renting is usually
cheaper than owning.

Yes, yes, I know.  You can go down to Acme rent-a-car, rent a car on a
week-long special for $109, and drive 10,000 miles -- a mere 1,400 miles
a day, or 25.9 hours per day at 55mph -- for a pittance per mile.  So what.

Now here's a thought.  In an airplane, you may be able to get where
you're going in many fewer miles than you can if you go by road -- I'd
guess 20% better is not unusual.  So, that means you get to discount
the $.51/mile by 20% to yield $.41/mile, which is cheaper than
$0.43/mile.  And if you discount the $0.42/mile, you're down to a true
bargain -- only $0.36/mile!

Observations:
    Depending on how much you drive, how much you fly, how expensive a
    car you own, and how frequently you trade in your car, these
    numbers can vary substantially.  My auto costs are actually higher
    than shown here; my airplane costs, probably a bit lower.

    If I substitute real figures for my real car, the capital cost goes
    up from $0.20/mile to $0.36/mile.  The car is leased, so this is in
    fact a relatively precise figure.  That means that _my_ car costs
    $.56/mile to drive.  Ouch.  I should ride my bicycle more.  :-)

    If I substitute real figures for my real airplane, the costs go _down_
    somewhat because I do fly it about 250-300 hours/year.  Knock off about
    $.11/mile from the registration/tax/tiedown/insurance column -- and the
    airplane's down to $0.40/mile.  I _do_ fly my airplane more!  :-)

I know.  Lies, damn lies, and statistics.  These aren't statistics.  They're
neither standard nor devious.  They're just numbers.  They're trying not to
lie.  But you can make them lie too, if you want to.  Just strap them to this
conveniently-located railroad track...

						Geoff
Newsgroups: rec.aviation